.pl 66 .mt 5 .mb 5 .hm 2 .fm 2 .po 11 .cw 10 .uj off .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! BSR X3.131-198_ NOTE Revisio 17B consists of changes made by the X3T9/84-40 REV 1B X3T9. task group at their December 10, 1985 meeting. X3T9.2/82-2 These changes were made in order to make the X3T9.2 REV 17B draft proposed standard consisten wit th IS/TC9/SC1 draf proposal Se pag 1. fo change pag list. draft proposed American National Standard for information systems - SMALL COMPUTER SYSTEM INTERFACE (SCSI) December 16, 1985 Secretariat Computer and Business Equipment Manufacturers Association Abstract Thi standar define mechanical electrical an functiona requirement fo attachin smal computer wit eac othe an wit low- t medium-performanc intelligen peripheral suc a rigi disks flexibl disks magneti tap devices printers an optica disks Th resultin interfac facilitate th interconnectio o smal computer an intelligen peripheral an thu provide commo interfac specificatio fo bot system integrator an supplier o intelligen peripherals. POINTS OF CONTACT: William E. Burr (X3T9.2 Chairman) John B. Lohmeyer (X3T9.2 Vice Chairman) U.S. Department of Commerce NCR Corporation National Bureau of Standards 3718 N. Rock Road Technology A-216 Wichita, KS 67226 Gaithersburg, MD 20899 (316) 688-8703 (301) 921-3723 .pa .he Small Computer System Interface X3T9.2/82-2 - Rev. 17B 12/16/85 .fo 1.1 CHANGED PAGE LIST A thei December 10, 198 meeting th X3T9. tas grou mad numbe o change t Revisio 1 o thi document (Revisio 17 wa distribute a th meetin proposin som o th changes th remainde o th change wer mad a th meeting. Th primar reaso fo makin thes change i t kee thi documen consisten wit th ISO/TC97/SC1 SCS draf proposal Th page that have changed since Revision 17 ar liste below: Page Change ------- ------------------------------------------------------------------- 1 Changed revision number and date. 1.1 Replaced changed page list. 2 Editorial revisions to the foreword. 7-7.1 Revised the Table of Contents to reflect the document changes. 9 Added description of the contents of appendixes D - G. 12 Move sectio 4.3.2 Shielde Connector int Appendi D Merge sectio 4.3.1 int sectio 4.3. 12.1-12.2 \ 17-19 \ Deleted pages 19.1-19.4 / (Information moved to Appendix D). 21.1-21.2 / 20-21 Deleted second line of Table titles. 24 Redrew figures 4-5 through 4-7. 26 Redrew figure 4-9. 3 Clarifie tha multipl message ma b sen durin messag phase. 38 Clarification to the MESSAGE OUT phase error handling. 41 Redrew figures 5-1 and 5-2. 43 Editorial clarification. 49 Deleted "immediately". 50-50.1 Clarifie tha uni attentio conditio i o pe logica uni basis. Also clarified "other" command is other than REQUEST SENSE. 65-66 Added ISO version field to the INQUIRY data. 93.1 Revise Tabl 8-14. t referenc th lates X3B documen numbe and to refer to Appendix F for additional standards. 94-99 Editorial clarifications to the RESERVE and RELEASE commands. 113 Clarifie whic statu code ar t b returne o SEARC DAT commands. 119 Clarifie tha REA BLOC LIMIT return th target' capabilit a opposed to its current setting. 132 Added code values 0BH through 0DH to Table 9-14.1. 132.2-133 Editoria clarification t th RESERV UNI an RELEAS UNI commands. 147-149 Editoria clarification t th RESERV UNI an RELEAS UNI commands. 174-176.2 Revised Appendix A to make the figure legible. 182-183 Redrew figures C1 and C2. 184-192 Adde Appendi D Recommende Shielde Connectors Most of thi information was previously in section 4.3.2. 193-194 Added Appendix E, Conformance. 19-196 Adde Appendi F Additiona Mediu Typ an Densit Cod Standards. 197 Appendix G was previously Appendix D. Editorial clarification. .pa .pn 2 .fo # FOREWORD (This Foreword is not part of American National Standard X3.131-198_.) Th developmen o comparativel inexpensiv VLS devic controller hav recentl change th economic o interface fo smal syste storag devices Wher expensiv controlle logi wa onc share amon a man device a possible i man case i no make economi sens t buil controlle i eac device Thi i particularl tru fo hig-performanc storag devices wher th intimat interaction o th recordin medium th recordin mechanism an th recordin cod caus intersymbo interferenc an erro recover problem tha ar highl specifi t th chose technologies an ar bes resolve withi th devic itself Moreover th numbe o type o storag device fo smal computers an th industr tha build them hav grow dramaticall i th pas fe years I particular th emergenc o physicall small bu comparativel high-capacit an high-performanc fixed-mediu magneti dis device (virtuall non- existen i th lat 1970s bu multibillio dolla busines i th mid- 1980s ha drive th developmen o smal compute system an cause nee fo othe classe o devices suc a streamin cartridg tap drives fo backu an dat interchange. Becaus devic interface ar ver specifi t devic types man devic leve interfac standard woul b require t servic al smal compute devic types Becaus backplan buse resid a th cente o computers an hav dramati performanc effects man differen one ar neede fo differen syste requirements T connec ever backplan bu t ever devic interfac throug controlle woul requir a almos unbounde numbe o specifi controlle products I addition i man system today i i no th compute whic i "central" i i th storag facility Tha is on or tw larg capacit storag subsystem serv severa computers A interfac adapte t thi realit wa needed B 1982 al th need give abov wer widel recognize i th industr an b th member o X3T an it Tas Groups commercia smal syste paralle bus th Shugar Associate Syste Interfac (SASI) generall me th smal syste requirement fo device-independen periphera o syste bu an ha enjoye significan marke success I wa offere t X3T9. a th basi fo standard X3T9. chos th nam Smal Compute Syste Interfac (SCSI fo tha standar an bega wor a it Apri 198 meeting Th presen SCS dpAN i formalizatio an extensio o th SASI Man existin SAS device ar SCS compatible. Sinc Apri 1982 X3T9. ha hel plenar sessions a tw mont intervals plu numerou informa workin meetings Th origina SAS ha bee extende i numbe o ways including: (1 differentia electrica optio ha bee adde t allo us o longe cable (u t 2 meters i environment wher commo mod nois i concern (2 synchronou transfe optio ha bee develope allowin maximu transfe rate i th t megabyte per secon range. (3 A optiona "extended comman se ha bee added allowin fo ver larg capacit storag device ( bloc addres spac o 232 block versu 221 fo SASI) an Inquir command tha allo self-configurin drive software (4 Comman set fo magneti tap (bot start/sto an streaming) printers processors optica disks an read-onl optica disk hav bee adde t th propose SCS standard i additio t thos fo magneti disks Althoug i migh hav bee prematur i Apri 198 t clai tha SAS wa the d facto standard thi surel i th cas fo SASI/SCS today SCS compatibl hos adapters controllers an periphera device ar no widel manufacture aroun th world Hos adapter ar availabl fo mos smal computer wit accessibl backplan buses SCS controller ar widel availabl fo al th d jure an d facto standar magneti dis an magneti tap devic interfaces Smal high-capacit fixed-mediu magneti disks rigi removable-mediu magneti disks high-capacit Bernoulli-effec flexibl disks an othe closed-loo high-capacit flexibl dis products a wel a optica dis products ar al availabl wit integra SCS controllers SCS subsystem tha integrat bot rigid-dis an streaming-tap driv int singl packag ar als available SCS interfac chip ar available an som dis controlle chi set als provid SCS support. Sinc larg numbe o companie hav implemente an teste th SCS durin th developmen o th propose standard n separat tes progra ha bee deeme necessary A th Februar 198 meetin o X3T9.2 representative o th followin companie stated fo th record tha thei companie ha implemente an teste SCSI Adaptec Adaptiv Data Dat Technolog Corp. Fujits America Inc. NC Corp. an Shugar Corp Thi i no complet lis o companie implementin product usin SCS no i i promis b thes companie t offe SCS products Th SCS fill a urgen need provide fo th future an i consonan wit actua commercia practice Mos important th timin i right SCS catche th floodtid o new high-performanc storag device fo smal systems an promise t brin measur o neede orde t wha woul otherwis b chaoti an fragmente market Thi standar specifie th mechanical electrical an functiona requirement fo smal compute input/outpu bu interface an comman set fo periphera devic types particularl storag devices commonl use wit smal computers. Suggestion fo improvemen o thi standar wil b welcome The shoul b sen t th Compute an Busines Equipmen Manufacturer Association 31 Firs Street NW Suit 500 Washington DC 20001. Thi standar wa processe an approve fo submitta t ANS b America Nationa Standard Committe o Computer an Informatio Processing X3 Committe approva o th standar doe no impl tha al committe member vote fo it approval. .fo 2.1 .pa .pn 3 .fo # A th tim i approve thi standard th X Committe ha th followin members: T B DETERMINED .pa Subcommitte X3T o I/ interfaces whic reviewe thi standard ha th followin members: Delbert L. Shoemaker (Chairman) Ron Tranquilli (Vice Chairman) Bob Bender G. Atterbury (Alt) John Blagaila Charles Brill (Alt) Fred Ciechowski William E. Burr (Alt) George Clark Roger Cormier (Alt) Stephen W. Cooper Hank Dorris (Alt) Louis C. Domshy Thomas A. Fiers (Alt) Robert Dugan Henry Ginter (Alt) Ross H. Jaibaji William J. McClain (Alt) Patrick Lannan William Mosenthal, Jr. (Alt) Gene Milligan Kirk Moulton (Alt) Tom Morrow Mike Newton Gary S. Robinson Arnold John Roccati Floyd E. Ross Holly S. White (Note Th nam list o thi pag an th followin pag ar incomplet an they wil b update upo fina approva o thi standard.) .pa Tas Grou X3T9. o Lower-Leve Interfaces whic develope thi standard ha th followin members: William E. Burr (Chairman) John B. Lohmeyer (Vice Chairman) Ezra R. Alcudia Keith Amundsen (Alt) J. L. Amstutz Karen Anneberg (Alt) Bob Bender Charles Brill (Alt) John Blagaila Larry Boucher (Alt) Tom Briggs Paul Clement (Alt) David T. Cornaby George E. Clark (Alt) David F. Craft, Jr. Steve Cooper (Alt) Jay Cunningham Gary Crowell (Alt) Willard S. Davidson Jon Ericson (Alt) Terry Dawson Tom Fiers (Alt) Phil Devin Stephen Fitzgerald (Alt) Louis C. Domshy Marty Francis (Alt) Norm Dornseif William Homans (Alt) Alan Ebright J. V. Howell (Alt) Anita Freeman Skip Kilsdonk (Alt) Abe Gindi Jim Korpi (Alt) William A. Horton Lawrence J. Lamers (Alt) Frank Krulc Keith Mueller (Alt) Patrick E. Lannan Don Nanneman (Alt) Daniel Loski Doug Nolff (Alt) William C. Mavity Richard Reiser (Alt) Gene Milligan William H. Roberts (Alt) Bob Mortensen Floyd E. Ross (Alt) Gary S. Robinson D. Michael Robinson (Alt) Don Rodgers Jay Seashore (Alt) Arnold J. Roccati Chuck Spatafore (Alt) Jack Schiffhauer Jeff Stai (Alt) Ralph H. Schultz Paul Stavish (Alt) Moshe Segal Delbert L. Shoemaker Tim Slaton Robert N. Snively Adrienne Turenne Norm Zimmerman .pa T A B L E O F C O N T E N T S  1. Scope...................................................................8 2. Referenced Standard.....................................................9 3. Glossary and Conventions................................................9 3.1 Glossary...........................................................9 3.2 Editorial Conventions.............................................11 4. Physical Characteristics...............................................11 4.1 Physical Description..............................................11 4.2 Cable Requirements................................................11 4.3 Connector Requirements............................................12 4.4 Electrical Description............................................22 4.5 SCSI Bus..........................................................25 4.6 SCSI Bus Signals..................................................27 4.7 SCSI Bus Timing...................................................30 5. Logical Characteristics................................................31 5.1 SCSI Bus Phases...................................................31 5.2 SCSI Bus Conditions...............................................38 5.3 SCSI Bus Phase Sequences..........................................40 5.4 SCSI Pointers.....................................................42 5.5 Message System Specification......................................42 6. SCSI Commands .........................................................49 6.1 Command Implementation Requirements...............................50 6. Comman Descripto Block........................................50.1 6.3 Command Examples..................................................55 7. Command Descriptions for All Device Types..............................57 7.1 Group 0 Commands for All Device Types.............................57 7.2 Group 1 Commands for All Device Types.............................76 7.3 Group 2 Commands for All Device Types.............................79 7.4 Group 3 Commands for All Device Types.............................79 7.5 Group 4 Commands for All Device Types.............................79 7.6 Group 5 Commands for All Device Types.............................79 7.7 Group 6 Commands for All Device Types.............................79 7.8 Group 7 Commands for All Device Types.............................79 8. Command Descriptions for Direct-Access Devices.........................80 8.1 Group 0 Commands for Direct-Access Devices........................80 8.2 Group 1 Commands for Direct-Access Devices.......................104 9. Group 0 Command Descriptions for Sequential-Access Devices............117 10. Group 0 Command Descriptions for Printer Devices......................140 11. Group 0 Command Descriptions for Processor Devices....................152 12. Command Descriptions for Write-Once Read-Multiple Devices.............155 12.1 Group 0 Commands for Write-Once Read-Multiple Devices...........155 12.2 Group 1 Commands for Write-Once Read-Multiple Devices...........164 .pa 13. Command Descriptions for Read-Only Direct-Access Devices..............170 13.1 Group 0 Commands for Read-Only Direct-Access Devices............170 13.2 Group 1 Commands for Read-Only Direct-Access Devices............171 14. Status ...............................................................172 L I S T O F F I G U R E S  4-1 Nonshielded SCSI Device Connector.....................................13 4-2 Nonshielded Cable Connector...........................................15 4-5 Termination for Single-Ended Devices..................................24 4-6 Termination for Differential Devices..................................24 4-7 Differential Driver Protection Circuit (Optional).....................24 4-8 SCSI ID Bits..........................................................25 4-9 Sample SCSI Configurations............................................26 5-1 Phase Sequences without Arbitration...................................41 5-2 Phase Sequences with Arbitration......................................41 5-3 Simplified SCSI System................................................42 Appendixes Appendix A................................................................174 SCSI Signal Sequence Example Appendix A Figures A1: SCSI Timing Chart ...............................................175 Appendix B................................................................177 Typical Bus Phase Sequence Appendix C................................................................179 SCSI System Operation C1. Host Memory / Host Adapter / SCSI Controller Relationship........179 C2. SCSI READ Command Example........................................180 C3. I/O Channel Concept..............................................181 Appendix C Figures C1: Snapshot Prior to Initial Selection..............................182 C2: Snapshot Prior to Data Transfer..................................183 Appendix D................................................................184 Recommended Shielded Connectors D1. Shielded Connector, Alternative 1................................184 D2. Shielded Connector, Alternative 2................................184 D3. EUROCARD Boxes...................................................184 .pa .fo 7.1 Appendix D Figures D1: Female Shielded SCSI Cable Connector, Alternative 1..............185 D2: Male Shielded SCSI Device Connector, Alternative 1...............187 D3: Shielded SCSI Device Connector, Alternative 2....................189 D4: Shielded SCSI Cable Connector, Alternative 2.....................190 Appendix E................................................................193 Conformance E1. Alternatives.....................................................193 E2. Levels of Conformance............................................193 E3. Options..........................................................194 E4. Statement of Conformance.........................................194 Appendix F................................................................195 Additional Medium Type and Density Code Standards Appendix G................................................................197 Future Standardization .pa (This page is intentionally blank.) .fo 7.2 .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .pn 8 .fo Section 1 # 1. Scope Thi America Nationa Standar provide th mechanical electrical an functiona requirement fo smal compute input/outpu bu an comman set fo periphera devic type commonl use wit smal computers Th smal compute syste interface describe i thi standard i loca I/ bu tha ca b operate a dat rate u t megabyte pe secon dependin upo circui implementatio choices Th primar objectiv o th interfac i t provid hos computer wit devic independenc withi clas o devices Thus differen dis drives tap drives printers an eve communicatio device ca b adde t th hos computer(s withou requirin modification t generi syste hardwar o software Provisio i mad fo th additio o nongeneri feature an function throug vendo uniqu field an codes. Th interfac use logica rathe tha physica addressin fo al dat blocks Fo direc acces devices eac logica uni ma b interrogate t determin ho man block i contains logica uni ma coincid wit al o par o periphera device. Provisio i mad fo cabl length u t 2 meter usin differentia driver an receivers single-ende drive an receive configuratio i define fo cabl length o u t meter an i primaril intende fo application withi cabinet. Th interfac protoco include provisio fo th connectio o multipl initiator (SCS device capabl o initiatin a operation an multipl target (SCS device capabl o respondin t reques t perfor a operation) Optiona distribute arbitratio (i.e. bus-contentio logic i buil int th architectur o SCSI priorit syste award interfac contro t th highes priorit SCS devic tha i contendin fo us o th bus Th tim t complet arbitratio i independen o th numbe o device that ar contendin an ca b complete i les tha 1 microseconds. Th physica characteristic ar describe i Sectio 4 Ther ar tw electrica alternatives single-ende an differential Single-ende an differentia device ar electricall differen an shal no b mixe o th sam bus I addition ther ar severa options shielde o unshielde connector ma b use an parit ma o ma no b implemented. Sectio describe th logica characteristic o th interface A arbitratio optio i define t permi multipl initiator an t permi concurren I/ operations Al SCS device ar require t b capabl o operatin wit th define asynchronou transfe protocol I addition a optiona synchronou transfe protoco i defined Sectio als specifie messag protoco fo contro o th interface I mos cases message ar no directl apparen t th hos compute software Onl on message COMMAN COMPLETE i mandatory al other ar optiona an ar no necessaril implemented Not tha som option (e.g. synchronou transfer requir th implementatio o certai messages. Th SCS command structur i specifie i Sectio 6 Command ar classifie a mandator (M) extende (E) optiona (O) o vendo uniqu (V) SCS device shal implemen al mandator command define fo th appropriat devic typ an ma implemen othe command a well Extende SCS device shal implemen al extende plu al mandator command an ma implemen othe command a well Extende SCS device contai command tha facilitat th writin o self-configurin softwar driver tha ca "discover al necessar attribute withou prio knowledg o specifi periphera characteristic (suc a storag capacity) Extende command fo direc acces device als implemen ver larg logica bloc addres spac (232 blocks) althoug mandator command fo direc acces device implemen somewha smalle logica bloc addres spac (221 blocks). Sectio specifie thos command tha hav consisten meanin fo al devic types. Section throug 1 contai command fo direct-acces (eg. magneti disk) sequential-acces (e.g. magneti tape) printer processor write- once-read-multipl (e.g. optica disk) an read-onl direct-acces devices respectively Th command i eac o thes section ar uniqu t th devic type o the hav interpretations fields o feature tha ar specifi fo th devic type Thus fo example althoug th WRIT comman i use fo severa devic types i ha somewha differen for fo eac type wit differen parameter an meanings Therefore i i specifie separatel fo eac devic type. Sectio 1 describe th statu byt fo al devic types Statu i returne b target a th en o eac command Appendixe throug provid example o SCS signa sequences timing an phas sequences Appendi contain informatio o recommende shielde connectors Appendi contain informatio o conformanc statements Appendi contain informatio o othe standard relate t mediu type an densit code fo flexibl disk an magneti tapes Appendi contain informatio o futur extension t SCS tha ar bein considere b X3T9. However th appendixe ar no par o thi standard. .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 2 # 2. Referenced Standard Thi standar i intende fo us i conjunctio wit EI RS-485-1983 Standar fo Electrica Characteristic o Generator an Receiver fo us i Balanced Digital Multipoint Systems.1 .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 3 # 3. Glossary and Conventions 3.1 Glossary byte. In this standard, this term indicates an 8-bit (octet) byte. comman descripto bloc (CDB). Th structur use t communicat request fro a initiato t target. connect. Th functio tha occur whe a initiato select targe t star a operation. ____________ 1 Availabl fro th Electroni Industrie Association 200 Ey Stree NW Washington, D.C. 20006. .cp 56 disconnect. Th functio tha occur whe targe release contro o th SCS bus allowin i t g t th BU FRE phase. initiator. A SCS devic (usuall hos system tha request a operatio t b performe b anothe SCS device. INTERMEDIAT status. statu cod sen fro targe t a initiato upo completio o eac comman i se o linke command excep th las comman i th set. logica unit. physica o virtua devic addressabl throug target. logica uni numbe. A encoded three-bit identifie fo th logica unit. LSB. Least significant byte. LUN. Logical unit number. mm. Millimeter. ms. Millisecond. MSB. Most significant byte. ns. Nanosecond. one. A true signal value. periphera device. periphera tha ca b attache t a SCS devic (e.g. magnetic-disk printer optical-disk o magnetic-tape). reconnect. Th functio tha occur whe targe select a initiato t continu a operatio afte disconnect. reserved. Th ter use fo bits bytes fields an cod value tha ar se asid fo futur standardization. SCS address. Th octa representatio o th uniqu addres (0-7 assigne t a SCS device Thi addres woul normall b assigne an se i th SCS devic durin syste installation. SCS ID. Th bit-significan representatio o th SCS addres referrin t on o th signa line DB(7-0). SCS device. hos compute adapte o periphera controlle o a intelligen periphera tha ca b attache t th SCS bus. signa assertion. Th ac o drivin a signa t th tru state. signa negation. Th ac o drivin signa t th fals stat o allowin th cabl terminator t bia th signa t th fals stat (b placin th driver in the high impedance condition). signa release. Th ac o allowin th cabl terminator t bia th signa t th fals stat (b placin th drive i th hig impedanc condition). status. On byt o informatio sen fro targe t a initiato upo completio o each comman. target. A SCS devic tha perform a operatio requeste b a initiator. us. Microsecond. vendo unique. I thi standard thi ter indicate bits fields o cod value tha ar vendo specific. xxH. Number followe b capita subscrip ar hexadecima values Al othe number ar decima values zero. A false signal value. 3. Editoria Conventions. Certai word an term use i thi standar hav specifi meanin beyon th norma Englis meaning Thes word an term ar define eithe i th glossar (se 3.1 o i th tex wher the firs appea (e.g. initiator) Name o signals phases conditions messages commands statuses an sens key ar i al uppercas (e.g. REQUES SENSE) Lowercas i use fo word havin th norma Englis meaning. .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 4 # 4. Physical Characteristics Thi sectio contain th physica definitio o th SCSI Th connectors cables signals terminators an bu timin neede t implemen SCS ar covered. 4. Physica Description. SCS device ar daisy-chaine togethe usin commo cable Bot end o th cabl ar terminated Al signal ar commo betwee al SCS devices Tw driver/receive alternative ar available: (1 Single-ende driver an receivers whic allo maximu cabl lengt o si meter (primaril fo connectio withi cabinet) (2 Differentia driver an receivers whic allo maximu cabl lengt o 2 meter (primaril fo connectio outsid o cabinet) 4. Cabl Requirements. A idea impedanc matc wit cabl terminator implie cabl characteristi impedanc o 13 ohm (singled-ende option o 12 ohm (differentia option) I general cable wit thi hig o characteristi impedanc ar no available however impedance tha ar somewha lowe ar satisfactory characteristi impedanc o 10 ohm + 10 i recommende fo unshielde fla o twiste pai ribbo cable characteristi impedanc greate tha 9 ohm i preferre fo shielde cables however mos availabl cable hav somewha lowe characteristi impedance T minimiz discontinuitie an signa reflections cable o differen impedance shoul no b use i th sam bus Implementation ma requir trade-off i shieldin effectiveness cabl length th numbe o loads transfe rates an cos t achiev satisfactor syste operation. minimu conducto siz o 2 AW shal b employe t minimiz nois effect an ensur prope distributio o optiona terminato power. .cp 5 4.2. Single-Ende Cable. 50-conducto fla cabl o 25-signa twisted- pai cabl shal b used Th maximu cabl lengt shal b 6. meters. stu lengt o n mor tha 0. meter i allowe of th mainlin interconnectio withi an connecte equipment. SCS bu terminatio ma b interna t th SCS device tha ar a th end o th cable. 4.2. Differentia Cable. 50-conducto cabl o 25-signa twisted-pai cabl shal b used Th maximu cabl lengt shal b 2 meters. stu lengt o n mor tha 0. meter i allowe of th mainlin interconnectio withi an connecte equipment. SCS bu terminatio ma b interna t th SCS device tha ar a th end o th cable. 4. Connecto Requirements. Nonshielde connector ar specified Th nonshielde connector ar typicall use fo in-cabine applications Appendi define recommende shielde connector an thei pi assignments Thes connector ar typicall use fo externa application wher electromagneti compatibilit (EMC an electrostati discharg (ESD protectio ma b required Eithe typ o connecto ma b use wit th single-ende o differentia drivers. Th nonshielde SCS devic connecto (Figur 4-1 shal b 50-conducto connecto consistin o tw row o 2 mal pin wit adjacen pin 2.5 m (0. in apart shrou an heade bod shoul b used Th nonmatin portio o th connecto i show fo referenc only. Th nonshielde cabl connecto (Figur 4-2 shal b 50-conducto connecto consistin o tw row o 2 femal contact wit adjacen contact 2.54 mm (0.1 in) apart I i recommende tha keye connector b used. Th unshielde connecto pi assignment shal b a show i Tabl 4- fo single-ende driver an a show i Tabl 4- fo differentia drivers. .pa Figure 4-1a. Nonshielded SCSI Device Connector .pa ============================================================================== Dimensions Millimeters Inches ------------------------------------------------------------------------------ D1 2.54 0.100 D2* 82.80 3.260 D3 2.54 0.100 D4 4.83 0.190 D5* 8.51 0.335 D6* 72.64 2.860 D7* 78.74 3.100 D8* 13.94 0.549 D9 4.19 0.165 D10 6.09 0.240 D11 6.60 0.260 ============================================================================== NOTES: (1) Fifty Contacts on 2.54-mm (0.100-inch) spacing = 60.96 mm (2.40 inch). (2) Tolerances + 0.127 mm (0.005 inch) noncumulative. (3) Dimensions listed with asterisks (*) are shown for reference only. Figure 4-1b. Nonshielded SCSI Device Connector (Editor note Figure 4-1 an 4-1 ar t b combine int singl figur during the final editing.) .pa Figure 4-2a. Nonshielded Cable Connector .pa ============================================================================== Dimensions Millimeters Inches ------------------------------------------------------------------------------ C1 2.5400 0.100 C2 60.9600 2.400 C3 2.5400 0.100 C4 8.3570 0.329 C5 3.3025 0.130 C6 68.0720 2.680 C7 6.0960 0.240 C8* 8.1530 0.321 C9* 13.4870 0.531 C10* 3.8100 0.150 C11* 1.2700 0.050 C12* 6.0960 0.240 C13 32.3850 1.275 C14 3.3020 0.130 C15 7.4930 0.295 C16 2.6670 0.105 C17 1.6250 0.064 ============================================================================== NOTES: (1 Fift contact o 1.27-m (0.05-inch* staggere spacin 62.2 m (2.45 inch)*. (2) Tolerance + 0.12 m (0.00 inch noncumulative. (3) Dimensions listed with asterisks (*) are shown for reference only. Figure 4-2b. Nonshielded Cable Connector (Editor note Figure 4-2 an 4-2 ar t b combine int singl figur during the final editing.) (Page 17-1 an 19.1-19. ar deleted Th informatio previousl containe on these pages has been moved to Appendix D.) .pa .pn 20 .fo Section 4 # Table 4-1 Single-Ended Pin Assignments ============================================================================== Signal Pin Number ------------------------------------------------------------------------------ -DB(0) 2 -DB(1) 4 -DB(2) 6 -DB(3) 8 -DB(4) 10 -DB(5) 12 -DB(6) 14 -DB(7) 16 -DB(P) 18 GROUND 20 GROUND 22 GROUND 24 TERMPWR 26 GROUND 28 GROUND 30 -ATN 32 GROUND 34 -BSY 36 -ACK 38 -RST 40 -MSG 42 -SEL 44 -C/D 46 -REQ 48 -I/O 50 ============================================================================== NOTES: (1 Al od pin excep pi 2 shal b connecte t ground Pi 2 shoul b lef open Som product designe prio t th generatio o thi standar connecte thi pi t ground. (2 Th minu sig nex t th signal indicate activ low. .pa Table 4-2 Differential Pin Assignments ============================================================================== Signal Name Pin Number Signal Name ------------------------------------------------------------------------------ SHIELD GROUND 1 2 GROUND +DB(0) 3 4 -DB(0) +DB(1) 5 6 -DB(1) +DB(2) 7 8 -DB(2) +DB(3 1 -DB(3) +DB(4) 11 12 -DB(4) +DB(5) 13 14 -DB(5) +DB(6) 15 16 -DB(6) +DB(7) 17 18 -DB(7) +DB(P) 19 20 -DB(P) DIFFSENS 21 22 GROUND GROUND 23 24 GROUND TERMPWR 25 26 TERMPWR GROUND 27 28 GROUND +ATN 29 30 -ATN GROUND 31 32 GROUND +BSY 33 34 -BSY +ACK 35 36 -ACK +RST 37 38 -RST +MSG 39 40 -MSG +SEL 41 42 -SEL +C/D 43 44 -C/D +REQ 45 46 -REQ +I/O 47 48 -I/O GROUND 49 50 GROUND ============================================================================== NOTE: (1 SHIEL GROUN i optiona o som cables (Implementor note Som shielded flat ribbon cables use pin 1 as a connection to the shield.) .pa .pn 22 .fo Section 4 # 4.4 Electrical Description NOTE Fo thes measurements SCS bu terminatio i assume t b externa t th SCS device A SCS devic ma hav th provisio fo allowin optiona interna termination. 4.4. Single-Ende Alternative. Al assigne signal shal b terminate wit 22 ohm t + volt (nominal an 33 ohm t groun a eac en o th cable (Se Figur 4-5. Al signal shal us open-collecto o three-stat drivers. 4.4.1. Outpu Characteristics. Eac signa drive b a SCS devic shal hav th followin outpu characteristic whe measure a th SCS device' connector: Signal assertion = 0.0 volts dc to 0.4 volts dc Minimum driver output capability = 48 milliamps (sinking) at 0.5 volts dc Signal negation = 2.5 volts dc to 5.25 volts dc 4.4.1. Inpu Characteristics. Eac signa receive b a SCS devic shal hav th followin inpu characteristic whe measure a th SCS device' connector: Signal true = 0.0 volts dc to 0.8 volts dc Maximum total input load = -0.4 milliamps at 0.4 volts dc Signal false = 2.0 volts dc to 5.25 volts dc Minimum input hysteresis = 0.2 volts dc 4.4. Differentia Alternative. Al signal consis o tw line denote +SIGNA an -SIGNAL signa i tru whe +SIGNA i mor positiv tha -SIGNAL an signa i fals whe -SIGNA i mor positiv tha +SIGNAL Al assigne signal shal b terminate a eac en o th cabl a show i Figur 4-6. NOTE A a option th DIFFSEN signa o th connecto i reserve fo a activ hig enabl fo th differentia drivers I single-ende devic o terminato i inadvertentl connected thi signal i grounded disablin th drivers (Se Figur 4-7.) 4.4.2. Outpu Characteristics. Eac signa drive b a SCS devic shal hav th followin outpu characteristic whe measure a th SCS device' connector: VOL (Low-level output voltage) = 2. maximu a IOL (Low-leve outpu current 5 milliamps. VOH (High-level output voltage) = 3. minimu a IOH (High-leve outpu current -5 milliamps. VOD (Differential voltage) = 1. minimu wit common-mod voltag range fro - volt d t +1 volt dc. VOL an VOH shal b a measure betwee th outpu termina an th SCS device' logi groun reference. Th outpu characteristic shal additionall confor t EI RS-485-1983. .pa 4.4.2. Inpu Characteristics. Eac signa receive b a SCS devic shal hav th followin inpu characteristic whe measure a th SCS device' connector: II (Input current on either input) = + 2.0 milliamps maximum. NOTE Thes characteristic includ bot receiver an passiv drivers. Thi requiremen shal b me wit th inpu voltag varyin betwee -7 volt d an +1 volt dc wit powe o o off an wit th hysteresi equalin 3 millivolts minimum. Th inpu characteristic shal additionall confor t EI RS-485-1983. 4.4. Terminato Powe (Optional). Single-ende SCS device providin terminato powe (TERMPWR shal hav th followin characteristics: VTerm = 4.0 volts dc to 5.25 volts dc 80 milliamps minimu sourc driv capability 1. milliam maximu sin capabilit (excep fo th purpose o providin powe t a interna terminator wit 1. am recommende curren limitin (e.g. fuse). Differentia SCS device providin terminato powe (TERMPWR shal hav th followin characteristics: VTerm = 4.0 volts dc to 5.25 volts dc 60 milliamps minimu sourc driv capability 1. milliam maximu sin capabilit (excep fo th purpose o providin powe t a interna terminator wit 1. am recommende curren limitin (e.g. fuse). Th us o keye connector i recommende i SCS device tha provid terminato powe t preven accidenta groundin o misconnectio o terminato power. SCS device tha suppl terminato powe shal d s throug diod o simila semiconducto tha prevent th backflo o powe t th SCS device. .pa Figure 4-5. Termination for Single-Ended Devices Figure 4-6. Termination for Differential Devices Figure 4-7. Differential Driver Protection Circuit (Optional) .pa 4. SCS Bus. Communicatio o th SCS bu i allowe betwee onl tw SCS device a an give time Ther i maximu o eigh SCS devices Eac SCS devic ha a SCS I bi assigne a show i Figur 4-8. Whe tw SCS device communicat o th SCS bus on act a a initiato an th othe act a target Th initiato originate a operatio an th targe perform th operation A SCS devic usuall ha fixe rol a a initiato o target bu som device ma b abl t assum eithe role. A initiato ma addres u t eigh periphera device tha ar connecte t target A optio allow th addressin o u t 2,04 periphera device pe targe usin extende messages Thre sampl syste configuration ar show i Figur 4-9. DB(7) DB(6) DB(5) DB(4) DB(3) DB(2) DB(1) DB(0) <-- DATA BUS | | | | | | | | | | | | | | | SCSI ID = 0 | | | | | | | | | | | | | SCSI ID = 1 | | | | | | | | | | | SCSI ID = 2 | | | | | | | | | SCSI ID = 3 | | | | | | | SCSI ID = 4 | | | | | SCSI ID = 5 | | | SCSI ID = 6 | SCSI ID = 7 Figure 4-8. SCSI ID Bits .pa Figure 4-9. Sample SCSI Configurations .pa U t eigh SCS device ca b supporte o th SCS bus The ca b an combinatio o initiator an targets. Certai SCS bu function ar assigne t th initiato an certai SCS bu function ar assigne t th target Th initiato ma arbitrat fo th SCS bu an selec particula target Th targe ma reques th transfe o COMMAND DATA STATU, o othe informatio o th DAT BUS an i som case i ma arbitrat fo th SCS bu an reselec a initiato fo th purpos o continuin a operation. Informatio transfer o th DAT BU ar asynchronou an follo define REQ/AC handshak protocol On byt o informatio ma b transferre wit eac handshake A optio i defined fo synchronou dat transfer. 4. SCS Bu Signals. Ther ar tota o eightee signals Nin ar use fo contro an nin ar use fo data (Dat signal includ th parit signa option) Thes signal ar describe a follows: BS (BUSY). A "OR-tied signa tha indicate tha th bu i bein used. SE (SELECT). signa use b a initiato t selec targe o b targe t reselec a initiator. C/ (CONTROL/DATA). signa drive b targe tha indicate whethe CONTRO o DAT informatio i o th DAT BUS Tru indicate CONTROL. I/ (INPUT/OUTPUT). signa drive b targe tha control th directio o dat movemen o th DAT BU wit respec t a initiator Tru indicate inpu t th initiator Thi signa i als use t distinguis betwee SELECTIO an RESELECTIO phases. MS (MESSAGE). signa drive b targe durin th MESSAG phase. RE (REQUEST). signa drive b targe t indicat reques fo REQ/AC dat transfe handshake. AC (ACKNOWLEDGE). signa drive b a initiato t indicat a acknowledgmen fo REQ/AC dat transfe handshake. AT (ATTENTION). signa drive b a initiato t indicat th ATTENTIO condition. RS (RESET). A "OR-tied signa tha indicate th RESE condition. DB(7-0,P (DAT BUS). Eigh data-bi signals plu parity-bi signa tha for DAT BUS DB(7 i th mos significan bi an ha th highes priorit durin th ARBITRATIO phase Bi number significance an priorit decreas downwar t DB(0) dat bi i define a on whe th signa valu i tru an i define a zer whe th signa valu i false. Dat parit DB(P i odd Th us o parit i syste optio (i.e. syste i configure s tha al SCS device o bu generat parit an hav parit detectio enabled o al SCS device hav parit detectio disable o no implemented) Parit i no vali durin th ARBITRATIO phase. 4.6. Signa Values. Signal ma assum tru o fals values Ther ar tw method o drivin thes signals I bot cases th signa shal b activel drive true o asserted I th cas o OR-tie drivers th drive doe no driv th signa t th fals state rathe th bia circuitr o th bu terminator pull th signa fals wheneve i i release b th driver a ever SCS device I an drive i asserted the th signa i true I th cas o non-OR-tie drivers th signa ma b activel drive false o negated I thi standard whereve th ter negate i used i mean tha th signa ma b activel drive false o ma b simpl release (i whic cas th bia circuitr pull i false) a th optio o th implementor Th advantag t activel driv signal fals i tha th transitio fro tru t fals occur mor quickly an nois margin ma b somewha improved thi ma permi somewha faste dat transfer 4.6. OR-Tie Signals. Th BS an RS signal shal b OR-tie only I th ordinar operatio o th bus thes signal ar simultaneousl drive tru b severa drivers N signal othe tha BSY RST an DB(P ar simultaneousl drive b tw o mor drivers an an signa othe tha BS an RS ma emplo OR-tie o non-OR-tie drivers DB(P shal no b drive fals durin th ARBITRATIO phase Ther i n operationa proble i mixin OR-tie an non-OR-tie driver o signal othe tha BS an RST. 4.6. Signa Sources. Tabl 4- indicate whic typ o SCS devic i allowe t sourc eac signal N attemp i mad t sho i th sourc i drivin asserted drivin negated o i passive Al SCS devic driver tha ar no activ source shal b i th passiv state Not tha th RS signa ma b source b an SCS devic a an time. .pa Table 4-3 Signal Sources ============================================================================== Signals ---------------------------------------------------------- C/D, I/O, Bus Phase BSY SEL MSG, REQ ACK/ATN DB(7-0,P) ------------------------------------------------------------------------------ BUS FREE None None None None None ARBITRATION All Winner None None SCSI ID SELECTION I&T Initiator None Initiator Initiator RESELECTION I&T Target Target Initiator Target COMMAND Target None Target Initiator Initiator DATA IN Target None Target Initiator Target DATA OUT Target None Target Initiator Initiator STATUS Target None Target Initiator Target MESSAGE IN Target None Target Initiator Target MESSAGE OUT Target None Target Initiator Initiator ============================================================================== All: Th signa shal b drive b al SCS device tha ar activel arbitrating. SCSI ID: uniqu dat bi (th SCS ID shal b drive b eac SCS devic tha i activel arbitrating th othe seve dat bit shal b release (i.e. no driven b thi SCS device Th parit bi (DB(P) ma b undrive o drive t th tru state bu shal neve b drive t th fals stat durin thi phase. I&T: Th signa shal b drive b th initiator target o both a specifie i th SELECTIO phas an RESELECTIO phase. Initiator: I thi signa i driven i shal b drive onl b th activ initiator. None: Th signa shal b released tha is no b drive b an SCS device Th bia circuitr o th bu terminator pull th signal t th fals state. Winner: Th signa shal b drive b th on SCS devic tha win arbitration. Target: I th signa i driven i shal b drive onl b th activ target. .pa 4. SCS Bu Timing. Unles otherwis indicated th delay-tim measurement fo eac SCS device show i 4.7. throug 4.7.14 shal b calculate fro signa condition existin a tha SCS device' ow SCS bu connection Thus thes measurement (excep cabl ske delay ca b mad withou considerin delay i th cable. 4.7. Arbitratio Dela (2. microseconds). Th minimu tim a SCS devic shal wai fro assertin BS fo arbitratio unti th DAT BU ca b examine t se i arbitratio ha bee won Ther i n maximu time. 4.7. Assertio Perio (9 nanoseconds). Th minimu tim tha targe shal asser RE whil usin synchronou dat transfers Also th minimu tim tha a initiato shal asser AC whil usin synchronou dat transfers. 4.7. Bu Clea Dela (80 nanoseconds). Th maximu tim fo a SCS devic t sto drivin al bu signal after: (1 Th BU FRE phas i detecte (BS an SE bot fals fo bu settl delay) (2 SE i receive fro anothe SCS devic durin th ARBITRATIO phase (3) The transition of RST to true. NOTE Fo th firs conditio above th maximu tim fo a SCS devic t clea th bu i 120 nanosecond fro BS an SE firs becomin bot false I a SCS devic require mor tha bu settl dela t detec BU FRE phase i shal clea th bu withi bu clea dela minu th exces time. 4.7. Bu Fre Dela (80 nanoseconds). Th minimu tim tha a SCS devic shal wai fro it detectio o th BU FRE phas (BS an SE bot fals fo bu settl delay unti it assertio o BS whe goin t th ARBITRATIO phase. 4.7. Bu Se Dela (1. microseconds). Th maximu tim fo a SCS devic t asser BS an it SCS I bi o th DAT BU afte i detect BU FRE phas (BS an SE bot fals fo bu settl delay fo th purpos o enterin th ARBITRATIO phase. 4.7. Bu Settl Dela (40 nanoseconds). Th tim t wai fo th bu t settl afte changin certai contro signal a calle ou i th protoco definitions. 4.7. Cabl Ske Dela (1 nanoseconds). Th maximu differenc i propagatio tim allowe betwee an tw SCS bu signal whe measure betwee an tw SCS devices. 4.7. Dat Releas Dela (40 nanoseconds). Th maximu tim fo a initiato t releas th DAT BU signal followin th transitio o th I/ signal from false to true. 4.7.9 Deske Dela (4 nanoseconds). Th minimu tim require fo deske o certai signals. 4.7.10 Hol Tim (4 nanoseconds). Th minimu tim adde betwee th assertio o RE o AC an th changin o th dat line t provid hol tim i th initiato o target respectively whil usin synchronou dat transfers. 4.7.11 Negatio Perio (9 nanoseconds). Th minimu tim tha targe shal negat RE whil usin synchronou dat transfers Also th minimu tim tha a initiato shal negat AC whil usin synchronou dat transfers. 4.7.12 Rese Hol Tim (2 microseconds). Th minimu tim fo whic RS i asserted Ther i n maximu time. 4.7.13 Selectio Abor Tim (20 microseconds). Th maximu tim tha targe (o initiator shal tak fro it mos recen detectio o bein selecte (o reselected unti assertin BS response Thi timeou i require t ensur tha targe (o initiator doe no asser BS afte SELECTIO (o RESELECTION phas ha bee aborted Thi i no th selectio timeou period se Section 5.1.3. an 5.1.4. fo complet description. 4.7.14 Selectio Timeou Dela (25 milliseconds recommended). Th minimu tim tha a initiato (o target shoul wai fo BS respons durin th SELECTIO (o RESELECTION phas befor startin th timeou procedure Not tha thi i onl recommende tim period Th specification fo th periphera device shal b consulte fo th actua timin requirements. 4.7.15 Transfe Perio (se durin MESSAG phase). Th Transfe Perio specifie th minimu tim allowe betwee th leadin edge o successiv RE pulse an o successiv AC pulse whil usin synchronou dat transfers (Se Sections 5.1.5.2 and 5.5.5.) .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 5 # 5. Logical Characteristics 5. SCS Bu Phases. Th SCS architectur include eigh distinc phases: BUS FREE phase ARBITRATION phase SELECTION phase RESELECTION phase COMMAND phase \ DATA phase \ These phases are collectively termed the STATUS phase / information transfer phases. MESSAGE phase / Th SCS bu ca neve b i mor tha on phas a an give time Unles otherwis note i th followin descriptions signal tha ar no mentione shal no b asserted. 5.1. BU FRE Phase. Th BU FRE phas i use t indicat tha n SCS devic i activel usin th SCS bu an tha i i availabl fo subsequen users. SCS device shal detec th BU FRE phas afte SE an BS ar bot fals fo a leas bu settl delay. SCS device shal releas al SCS bu signal withi bu clea dela afte BS an SE becom continuousl fals fo bu settl delay I a SCS devic require mor tha bu settl dela t detec th BU FRE phas the i shal releas al SCS bu signal withi bu clea dela minu th exces tim t detec th BU FRE phase Th tota tim t clea th SCS bu shal no excee bu settl dela plu bu clea delay. 5.1. ARBITRATIO Phase. Th ARBITRATIO phas allow on SCS devic t gai contro o th SCS bu s tha i ca assum th rol o a initiato o target. NOTE Implementatio o th ARBITRATIO phas i syste option System tha d no implemen thi optio ca hav onl on initiator Th ARBITRATIO phas i require fo system tha us th RESELECTIO phase. Th procedur fo a SCS devic t obtai contro o th SCS bu i a follows: (1 Th SCS devic shal firs wai fo th BU FRE phas t occur Th BU FRE phas i detecte wheneve bot BS an SE ar simultaneousl an continuousl fals fo minimu o bu settl delay (Implementor Note Thi bu settl dela i necessar becaus transmissio lin phenomeno know a "wire-O glitch ma caus BS t briefl appea false eve thoug i i bein drive true.) (2 Th SCS devic shal wai minimu o bu fre dela afte detectio o th BU FRE phas (i.e afte BS an SE ar bot fals fo bu settl delay befor drivin an signal (3 Followin th bu fre dela i Ste (2) th SCS devic ma arbitrat fo th SCS bu b assertin bot BS an it ow SCS ID howeve th SCS devic shal no arbitrat (i.e asser BS an it SCS ID i mor tha bu se dela ha passe sinc th BU FRE phas wa las observed (Implementor Note Ther i n maximu dela befor assertin BS an th SCS I followin th bu fre dela i Ste (2 a lon a th bu remain i th BU FRE phase However SCS device tha dela longe tha bu settl dela plu bu se dela fro th tim whe BS an SE firs becom fals ma fai t participat i arbitratio whe competin wit faste SCS devices.) (4 Afte waitin a leas a arbitratio dela (measure fro it assertio o BSY th SCS devic shal examin th DAT BUS I highe priorit SCS I bi i tru o th DAT BU (DB(7 i th highest) the th SCS devic ha los th arbitratio an th SCS devic ma releas it signal an retur t Ste (1) I n highe priorit SCS I bi i tru o th DAT BUS the th SCS devic ha wo th arbitratio an i shal asser SEL An othe SCS devic tha i participatin i th ARBITRATIO phas ha los th arbitratio an shal releas BS an it SCS I bi withi bu clea dela afte SE become true A SCS devic tha lose arbitratio ma retur t Ste (1). (5 Th SCS devic tha win arbitratio shal wai a leas bu clea dela plu bu settl dela afte assertin SE befor changin an signals. NOTE Th SCS I bi i singl bi o th DAT BU tha correspond t th SCS device' uniqu SCS address Al othe seve DATA BUS bit shal b release b th SCS device Parit i no vali durin th ARBITRATIO phase Durin th ARBITRATIO phase DB(P ma b undrive o drive t th tru state bu shal no b drive t th fals state. 5.1. SELECTIO Phase. Th SELECTIO phas allow a initiato t selec targe fo th purpos o initiatin som targe functio (e.g. READ or WRITE command). NOTE Durin th SELECTIO phas th I/ signa shal b negate s tha thi phas ca b distinguishe fro th RESELECTIO phase. 5.1.3. Nonarbitratin Systems. I system wit th ARBITRATIO phas no implemented th initiato shal firs detec th BU FRE phas an the wai minimu o bu clea delay Then excep i certai singl initiato environment wit initiator employin th singl initiato optio (se 5.1.3.4) th initiato shal asser th desire target' SCS I an it ow initiato SCS I o th DAT BUS Afte tw deske delay th initiato shal asser SEL. 5.1.3. Arbitratin Systems. I system wit ARBITRATIO phas implemented th SCS devic tha wo th arbitratio ha bot BS an SE asserte an ha delaye a leas bu clea dela plu bu settl dela befor endin th ARBITRATIO phase Th SCS devic tha wo th arbitratio become a initiato b releasin I/O Excep i certai singl initiato environment wit initiator employin th singl initiato optio (se 5.1.3.4) th initiato shal se th DAT BU t valu whic i th O o it SCS I bi an th target' SCS I bit Th initiato shal the wai a leas tw deske delay an releas BSY Th initiato shal the wai a leas bu settl dela befor lookin fo respons fro th target. 5.1.3. Al Systems. I al systems th targe shal determin tha i i selecte whe SE an it SCS I bi ar tru an BS an I/ ar fals fo a leas bu settl delay Th selecte targe ma examin th DAT BU i orde t determin th SCS I o th selectin initiato unles th initiato employe th singl initiato optio (se 5.1.3.4) Th selecte targe shal the asser BS withi selectio abor tim o it mos recen detectio o bein selected thi i require fo correc operatio o th timeou procedure I system wit parit implemented th targe shal no respon t selectio i ba parit i detected Also i mor tha tw SCS I bit ar o th DAT BUS th targe shal no respon t selection. A leas tw deske delay afte th initiato detect BS i true i shal releas SE an ma chang th DAT BUS. 5.1.3. Singl Initiato Option. Initiator tha d no implemen th RESELECTIO phas an d no operat i th multipl initiato environmen ar allowe t se onl th target' SCS I bi durin th SELECTIO phase Thi make i impossibl fo th targe t determin th initiator' SCS ID. 5.1.3. Selectio Timeou Procedure. Tw optiona selectio timeou procedure ar specifie fo clearin th SCS bu i th initiato wait minimu o selectio timeou dela an ther ha bee n BS respons fro th target: (1 Optionally, th initiato shall asser th RS signal (se 5.2.2). (2 Optionally th initiato shal continu assertin SE an shal releas th DAT BUS I th initiato ha no detecte BS t b tru afte a leas selectio abor tim plu tw deske delays th initiato shal releas SE allowin th SCS bu t g t th BU FRE phase SCS device shal ensur tha whe respondin t selectio tha th selectio wa stil vali withi selectio abor tim o thei assertio o BSY Failur t compl wit thi requiremen coul resul i a imprope selectio (tw target connecte t th sam initiator wron targe connecte t a initiator o targe connecte t n initiator). 5.1. RESELECTIO Phas (Optional). RESELECTIO i a optiona phas tha allow targe t reconnec t a initiato fo th purpos o continuin som operatio tha wa previousl starte b th initiato bu wa suspende b th target (i.e. th targe disconnecte b allowin BU FRE phas t occu befor th operatio wa complete). 5.1.4. RESELECTION. RESELECTIO ca onl b use i system tha hav ARBITRATIO phas implemented. Upo completin th ARBITRATIO phase th winnin SCS devic ha bot BS an SE asserte an ha delaye a leas bu clea dela plu bu settl delay Th winnin SCS devic become targe b assertin th I/ signal Th winnin SCS devic shal als se th DAT BU t valu tha i th O o it SCS I bi an th initiator' SCS I bit Th targe shal wai a leas tw deske delay an releas BSY Th targe shal the wai a leas bu settl dela befor lookin fo respons fro th initiator. Th initiato shal determin tha i i reselecte whe SEL I/O an it SCS I bi ar tru an BS i fals fo a leas bu settl delay Th reselecte initiato ma examin th DAT BU i orde t determin th SCS I o th reselectin target Th reselecte initiato shal the asser BS withi selectio abor tim o it mos recen detectio o bein reselected thi i require fo correc operatio o th timeou procedure I system wit parit implemented th initiato shal no respon t RESELECTIO i ba parit i detected Also th initiato shal no respon t RESELECTIO i mor tha tw SCS I bit ar o th DAT BUS Afte th targe detect BSY i shal als asser BS an wai a leas tw deske delay an the releas SEL Th targe ma the chang th I/ signa an th DAT BUS Afte th reselecte initiato detect SE false i shal releas BSY Th targe shal continu assertin BS unti th targe i read t relinquis th SCS bus NOTE Whe th targe i assertin BSY transmissio lin phenomeno know a "wire-O glitch ma caus BS t appea fals fo u t round-tri propagatio dela followin th releas o BS b th initiator Thi i th reaso wh th BU FRE phas i recognize onl afte bot BS an SE ar continuousl fals fo minimu o bu settl delay Cable longe tha 2 meters shoul no b use eve i th chose driver receiver an cabl provid adequat nois margins becaus the increas th duratio o th glitc an coul caus SCS device t inadvertentl detec th BU FRE phase. 5.1.4. RESELECTIO Timeou Procedure. Tw optiona RESELECTIO timeou procedure ar specifie fo clearin th SCS bu durin RESELECTIO phas i th targe wait minimu o selectio timeou perio an ther ha bee n BS respons fro th initiator (1 Optionally, th target shall asser th RS signal (se 5.2.2). (2 Optionally th targe shal continu assertin SE an I/ an shal releas al DAT BU signals I th targe ha no detecte BS t b tru afte a leas selectio abor tim plu tw deske delays th targe shal releas SE an I/ allowin th SCS bu t g t th BU FRE phase SCS device tha respon t RESELECTIO shal ensur tha th RESELECTIO wa stil vali withi selectio abor tim o thei assertio o BSY Failur t compl wit thi requiremen coul resul i a imprope reselectio (tw initiator connecte t th sam targe o th wron initiato connecte t target). 5.1. Informatio Transfe Phases. NOTE Th COMMAND DATA STATU, an MESSAG phase ar al groupe togethe a th informatio transfe phase becaus the ar al use t transfe dat o contro informatio vi th DAT BUS Th actua content o th informatio i beyon th scop o thi section. Th C/D I/, an MS signal ar use t distinguis betwee th differen informatio transfe phases (Se Tabl 5-1. Th targe drive thes thre signal an therefor control al change fro on phas t another Th initiato ca reques MESSAG OU phas b assertin ATN whil th targe ca caus th BU FRE phas b releasin MSG C/D I/O an BSY. Table 5-1 Information Transfer Phases ============================================================================== Signal ----------- MSG C/D I/O Phase Name Direction Of Transfer Comment ------------------------------------------------------------------------------ 0 0 0 DATA OUT Initiator to target \ Data 0 0 1 DATA IN Initiator from target / Phase 0 1 0 COMMAND Initiator to target 0 1 1 STATUS Initiator from target 1 0 0 * 1 0 1 * 1 1 0 MESSAGE OUT Initiator to target \ Message 1 1 1 MESSAGE IN Initiator from target / Phase ============================================================================== Key: 0 = False, 1 = True, * = Reserved for future standardization. Th informatio transfe phase us on o mor REQ/AC handshake t contro th informatio transfer Eac REQ/AC handshak allow th transfe o on byt o information Durin th informatio transfe phase BS shal remai tru an SE shal remai false Additionally durin th informatio transfe phases th targe shal continuousl envelop th REQ/AC handshake(s wit C/D I/O an MS i suc manne tha thes contro signal ar vali fo bu settl dela befor th assertio o RE o th firs handshak an remai vali unti th negatio o AC a th en o th las handshake. 5.1.5. Asynchronou Informatio Transfer. Th targe shal contro th directio o informatio transfe b mean o th I/ signal Whe I/ i true informatio shal b transferre fro th targe t th initiator Whe I/ i false informatio shal b transferre fro th initiato t th target. I I/ i tru (transfe t th initiator) th targe shal firs driv DB(7-0,P t thei desire values dela a leas on deske dela plu cabl ske delay the asser REQ DB(7-0,P shal remai vali unti AC i tru a th target Th initiato shal rea DB(7-0,P afte RE i true the signa it acceptanc o th dat b assertin ACK Whe AC become tru a th target th targe ma chang o releas DB(7-0,P an shal negat REQ Afte RE i fals th initiato shal the negat ACK Afte AC i fals th targe ma continu th transfe b drivin DB(7-0,P an assertin REQ a describe above. I I/ i fals (transfe t th target th targe shal reques informatio b assertin REQ Th initiato shal driv DB(7-0,P t thei desire values dela a leas on deske dela plu cabl ske dela an asser ACK Th initiato shal continu t driv DB(7-0,P unti RE i false Whe AC become tru a th target th targe shal rea DB(7-0,P) the negat REQ Whe RE become fals a th initiator th initiato ma chang o releas DB(7-0,P an shal negat ACK Th targe ma continu th transfe b assertin REQ a describe above. 5.1.5. Synchronou Dat Transfe (Optional). Synchronou dat transfe i optional an ma b use onl i th dat phas i previousl agree t b th initiato an targe throug th messag syste (se SYNCHRONOU DAT TRANSFE REQUES message 5.5.5) Th message determin th us o synchronou mod b bot SCS device an establis REQ/AC offse an transfe period. Th REQ/AC offse specifie th maximu numbe o RE pulse tha ca b sen b th targe i advanc o th numbe o AC pulse receive fro th initiator establishin pacin mechanism I th numbe o RE pulse exceed th numbe o AC pulse b th REQ/AC offset th targe shal no asser RE unti th nex AC puls i received requiremen fo successfu completio o th dat phas i tha th numbe o AC an RE pulse b equal Th targe shal asser th RE signa fo minimu o a assertio period Th targe shal wai a leas th greate o transfe perio fro th las transitio o RE t tru o minimu o negation perio fro th las transitio o RE t fals befor assertin th RE signal. Th initiato shal sen on puls o th AC signa fo eac RE puls received Th initiato shal asser th AC signa fo minimu o a assertio period Th initiato shal wai a leas th greate o transfe perio fro th las transitio o AC t tru o fo minimu o negatio perio fro th las transitio o AC t fals befor assertin th AC signal. I I/ i tru (transfe t th initiator) th targe shal firs driv DB(7-0,P t thei desire values wai a leas on deske dela plu on cabl ske delay the asser REQ DB(7-0,P shal b hel vali fo minimu o on deske dela plu on cabl ske dela plu on hol tim afte th assertio o REQ Th targe shal asser RE fo minimu o a assertio period Th targe ma the negat RE an chang o releas DB(7- 0,P) Th initiato shal rea th valu o DB(7-0,P withi on hol tim o th transitio o RE t true Th initiato shal the respon wit a AC pulse. I I/ i fals (transfe t th target) th initiato shal transfe on byt fo eac RE puls received Afte receivin RE pulse th initiato shal firs driv DB(7-0,P t thei desire values dela a leas on deske dela plu one cabl ske delay the asser ACK Th initiato shal hol DB(7-0,P vali fo a leas on deske dela plu on cabl ske dela plu on hol tim afte th assertio o ACK Th initiato shal asser AC fo minimu o a assertio period Th initiato may the negat AC an ma chang o releas DB(7-0,P) Th targe shal rea th valu o DB(7-0,P withi on hol tim o th transitio o AC t true. 5.1. COMMAN Phase. Th COMMAN phas allow th targe t reques comman informatio fro th initiator. Th targe shal asser th C/ signa an negat th I/ an MS signal durin th REQ/AC handshake(s o thi phase. 5.1. Dat Phase. Th dat phas i ter tha encompasse bot th DAT I phas an th DAT OU phase. 5.1.7. DAT I Phase. Th DAT I phas allow th targe t reques tha dat b sen t th initiato fro th target. Th targe shal asser th I/ signa an negat th C/ an MS signal durin th REQ/AC handshake(s o thi phase. 5.1.7. DAT OU Phase. Th DAT OU phas allow th targe t reques tha dat b sen fro th initiato t th target. Th targe shal negat th C/D I/, an MS signal durin th REQ/AC handshake(s o thi phase. 5.1. STATU Phase. Th STATU phas allow th targe t reques tha statu informatio b sen fro th targe t th initiator. Th targe shal asser C/ an I/ an negat th MS signa durin th REQ/AC handshak o thi phase. 5.1. Messag Phase. Th messag phas i ter tha reference eithe MESSAG IN o MESSAG OU phase Multipl message ma b sen durin eithe phase Th firs byt transferre i eithe o thes phase shal b eithe single-byt messag o th firs byt o multiple-byt message Multiple-byt message shal b wholl containe withi singl messag phase. 5.1.9. MESSAG I Phase. Th MESSAG I phas allow th targe t reques tha message() b sen t th initiato fro th target. Th targe shal asser C/D I/O an MS durin th REQ/AC handshake(s o thi phase. 5.1.9. MESSAG OU Phase. Th MESSAG OU phas allow th targe t reques tha messag(s) b sen fro th initiato t th target Th targe ma invok thi phas a it convenienc i respons t th ATTENTIO conditio (se 5.2.1) create b th initiator. Th targe shal asser C/ an MS an negat I/ durin th REQ/AC handshake(s o thi phase Th targe shal handshak byte(s i thi phas unti AT goe false, unless an error occurs (see MESSAGE REJECT, 5.5.2). I th targe detect on o mor parit error(s o th messag byte(s received i ma indicat it desir t retr th messag(s) b assertin RE afte detectin AT ha gon fals an prio t changin t an othe phase Th initiator upo detectin thi condition shal resen al o th previou messag byte(s sen durin thi phase Whe resendin mor tha on messag byte th initiato shal asser AT prio t assertin AC o th firs byt an shal maintai AT asserte unti th las byt i sen a describe i 5.2.1. I th targe receive al o th messag byte(s successfull (i.e. n parit errors) i shal indicat tha i doe no wis t retr b changin t an informatio transfe phas othe tha th MESSAG OU phas an transfe a leas on byte Th targe ma als indicat tha i ha successfull receive th messag byte(s b changin t th BU FRE phas (e.g. ABOR o BU DEVIC RESE messages). 5.1.1 Signa Restriction Betwee Phases. Whe th SCS bu i betwee tw informatio transfe phases th followin restriction shal appl t th SCS bu signals: (1) The BSY, SEL, REQ, and ACK signals shall not change. (2 Th C/D I/O MSG an DAT BU signal ma change Whe switchin th DAT BU directio fro ou (initiato driving t i (targe driving) th targe shal dela drivin th DAT BU b a leas dat releas dela plu bu settl dela afte assertin th I/ signa an th initiato shal releas th DAT BU n late tha dat releas dela afte th transitio o th I/ signa t true Whe switchin th DAT BU directio fro i (targe driving t ou (initiato driving) th targe shal releas th DAT BU n late tha deske dela afte negatin th I/ signal. (3 Th AT an RS signal ma chang a define unde th description fo th ATTENTIO conditio (5.2.1) an RESE condition (5.2.2). 5. SCS Bu Conditions. Th SCS bu ha tw asynchronou conditions th ATTENTIO conditio an th RESE condition Thes condition caus th SCS devic t perfor certai action an ca alte th phas sequence. 5.2. ATTENTIO Condition. Th ATTENTIO conditio allow a initiato t infor targe tha th initiato ha messag ready Th targe ma ge thi messag a it convenienc b performin MESSAG OU phase. Th initiato create th ATTENTIO conditio b assertin AT a an tim excep durin th ARBITRATIO o BU FRE phases. Th target ma respon wit th MESSAG OU phase. Th initiato shal kee AT asserte i mor tha on byt i t b transferred Th initiato ma negat th AT signa a an tim excep it shal no negat th AT signa whil th AC signa i asserte durin MESSAG OU phase Normally th initiato negate AT whil RE i tru an ACK is false during the last REQ/ACK handshake of the MESSAGE OUT phase. 5.2. RESE Condition. Th RESE conditio i use t immediatel clea al SCS device fro th bus Thi conditio shal tak precedenc ove al othe phase an conditions An SCS devic ma creat th RESE conditio b assertin RS fo minimu o rese hol time Durin th RESE condition th stat o al SCS bu signal othe tha RS i no defined. Al SCS device shal releas al SCS bu signal (excep RST withi bu clea dela o th transitio o RS t true Th BU FRE phas alway follow th RESE condition. Th effec o th RESE conditio o uncomplete commands SCS devic reservations an SCS devic operatin mode i determine b whethe th SCS devic ha implemente th "hard RESE optio o th "soft RESE optio (on o whic shal b implemented a define i 5.2.2. an 5.2.2.2. 5.2.2. "Hard RESE Option. SCS device tha implemen th "hard RESE option upo detectio o th RESE condition shall: (1) Clear all uncompleted commands (2) Release all SCSI device reservations (3 Retur an SCS devic operatin mode (MOD SELECT PREVENT/ALLO MEDIU REMOVA commands etc t thei defaul conditions. 5.2.2. "Soft RESE Option. SCS device tha implemen th "soft RESE option upo detectio o th RESE condition shall: (1 Attemp t complet an uncomplete command tha wer full identified (2) Preserve all SCSI device reservations (3 Preserv an SCS devic operatin mode (MOD SELECT PREVENT/ALLO MEDIU REMOVA commands etc) Th "soft RESE optio allow singl initiato t rese th SCS bu withou disturbin th operatio o othe initiator i multipl initiato system T ensur prope operatio th followin condition shal b met: (1 A initiato shal no conside comman t b full identifie unti th IDENTIF messag i sen t th targe an th targe respond b changin t an othe informatio transfe phas an request tha a leas on byt b transferred. (2 targe shal conside comman t b full identifie whe i successfull receive th IDENTIF message. (3 I a initiato select logica uni fo whic ther alread i a activ comman fo th sam initiator th targe shal clea th origina comman an perfor th ne command. (4 I targe reselect a initiato t continu comman fo whic th initiato ha n record th initiato shal abor tha comman b sendin th ABOR message. (5 A initiato shal conside comman t b complete whe i negate AC fo successfull receive COMMAN COMPLET message. (6 targe shal conside comman t b complete whe i detect th fals transitio o AC fo th COMMAN COMPLET messag wit th AT signa false. (7 A initiato shal no negat AC fo th SAV DAT POINTE messag unti i ha actuall save th dat pointe fo th operation. (8 targe shal conside th dat pointe t b save whe i detect th fals transitio o AC fo th SAV DAT POINTE messag wit th AT signa false. (9 I th RESE conditio occur betwee th tim tha th targe assert RE fo th SAV DAT POINTE messag an i detect th fals transitio o ACK th targe shal terminat th comman wit CHEC CONDITIO status I extende sens i implemented th targe shal se th sens ke t ABORTE COMMAND Thi i necessar becaus th targe canno determin whethe th dat pointe ha actuall bee saved. NOTE I th AT signa i tru i condition (6 o (8) th targe woul normall switc t MESSAG OU phas an attemp t transfe messag byte I th RESE conditio occur befor i i abl t successfull receiv th messag byte th targe shal assum tha th initiato ma no hav successfull receive th COMMAN COMPLET messag o th SAV DAT POINTE message I th cas o COMMAN COMPLET message th targe shal reselec th initiato an attemp t sen th COMMAN COMPLET messag again I th cas o th SAV DAT POINTE message th targe shal reselec th initiato and terminate the command as described in condition (9). 5. SCS Bu Phas Sequences. Th orde i whic phase ar use o th SCS bu follow prescribe sequence. I al systems th RESE conditio ca abor an phas an i alway followe b th BU FRE phase Also an othe phas ca b followe b th BU FRE phase. 5.3. Nonarbitratin Systems. I system wher th ARBITRATIO phas i no implemented th allowabl sequence shal b a show i Figur 5-1 Th norma progressio i fro th BU FRE phas t SELECTION an fro SELECTIO t on o mor o th informatio transfe phase (COMMAND DATA STATUS o MESSAGE). 5.3. Arbitratin Systems. I system wher th ARBITRATIO phas i implemented th allowabl sequence shal b a show i Figur 5-2 Th norma progressio i fro th BU FRE phas t ARBITRATION fro ARBITRATIO t SELECTIO o RESELECTION an fro SELECTIO o RESELECTIO t on o mor o th informatio transfe phase (COMMAND DATA STATUS o MESSAGE). 5.3. Al Systems. Ther ar n restriction o th sequence betwee informatio transfe phases phas typ ma eve b followe b th sam phas typ (e.g. dat phas ma b followe b anothe dat phase). .pa Figure 5-1. Phase Sequences without Arbitration Figure 5-2. Phase Sequences with Arbitration .pa 5. SCS Pointers. Conside th syste show i Figur 5- i whic a initiato an targe communicat o th SCS bu i orde t execut command ------------------------- ------------------------- | Function | | Initiator|-----------------| Target | | Function | | Origin | | Path | SCSI BUS | Path | | Execution| | | | Control |-----------------| Control | | | ------------------------- ------------------------- Initiator Target Figure 5-3. Simplified SCSI System Th SCS architectur provide fo tw set o thre pointer withi eac initiator Th pointer resid i th initiato pat control Th firs se o pointer ar know a th curren (o active pointers Thes pointer ar use t represen th stat o th interfac an poin t th nex command data o statu byt t b transferre betwee th initiator' memor an th target Ther i onl on se o curren pointer i eac initiator Th curren pointer ar use b th targe currentl connecte t th initiator. Th secon se o pointer ar know a th save pointers Ther i on se o save pointer fo eac comman tha i currentl activ (whethe o no i i currentl connected) Th save comman pointe alway point t th star o th comman descripto bloc (se 6.2 fo th curren command Th save statu pointe alway point t th star o th statu are fo th curren command A th beginnin o eac command th save dat pointe point t th star o th dat area I remain a thi valu unti th targe send SAV DAT POINTE messag (se 5.5.2 t th initiator I respons t thi message th initiato store th valu o th curren dat pointe int th save dat pointer Th targe ma restor th curren pointer t thei save value b sendin RESTOR POINTER messag (se 5.5.2 t th initiator Th initiato move th save valu o eac pointe int th correspondin curren pointer Wheneve a SCS devic disconnect fro th bus onl th save pointe value ar retained Th curren pointe value ar restore fro th save value upo th nex reconnection. 5. Messag Syste Specification. Th messag syste allow communicatio betwee a initiato an targe fo th purpos o physica pat management. 5.5. Messag Protocol. Al SCS device shal implemen th COMMAN COMPLET message functiona SCS devic ca b constructe withou usin an o th othe message i th logica uni numbe i specifie i th comman descripto block Th remainde o thi sectio deal wit th additiona requirement o SCS device tha suppor message othe tha COMMAN COMPLETE. SCS device indicat thei abilit t accommodat mor tha th COMMAN COMPLET messag b assertin o respondin t th AT signal Th initiato indicate thi i th SELECTIO phas b assertin AT prio t th SCS bu conditio o SE true an BS false Th targe indicate it abilit t accommodat mor message b respondin t th ATTENTIO conditio wit th MESSAG OU phas afte goin throug th SELECTIO phase Fo SCS device tha suppor message othe tha COMMAN COMPLETE th firs messag sen b th initiato afte th SELECTIO phas shal b th IDENTIF message Thi allow th establishmen o th physica pat fo particula logica uni specifie b th initiator Afte th RESELECTIO phase th target' firs messag shal b IDENTIFY Thi allow th physica pat t b reestablishe fo th target' specifie logica uni number Unde som exceptiona conditions a initiato ma sen th ABOR messag o th BU DEVIC RESE messag instea o th IDENTIF message a th firs message Onl on logica uni numbe shal b identifie fo an on selectio sequence secon IDENTIF messag wit ne logica uni numbe shal no b issue befor th SCS bu ha bee release (BU FRE phase). Wheneve physica pat i establishe i a initiato tha ca accommodat disconnectio an reconnection th initiato shal ensur tha th activ pointer o th physica pat ar equa t th save pointer fo tha particula logica uni number (A implie restor pointer operatio occur a resul o connec o reconnect.) SCS device tha implemen an messag othe tha th COMMAN COMPLET messag shal als implemen th MESSAG REJEC message. Table 5-2 Message Codes ============================================================================== Code Type Description Direction ------------------------------------------------------------------------------ 00H M COMMAND COMPLETE In 01H O EXTENDED MESSAGE In Out 02H O SAVE DATA POINTER In 03H O RESTORE POINTERS In 04H O DISCONNECT In 05H O INITIATOR DETECTED ERROR Out 06H O ABORT Out 07H O MESSAGE REJECT In Out 08H O NO OPERATION Out 09H O MESSAGE PARITY ERROR Out 0AH O LINKED COMMAND COMPLETE In 0BH O LINKED COMMAND COMPLETE (WITH FLAG) In 0CH O BUS DEVICE RESET Out 0DH _ 7FH R Reserved Codes 80H _ FFH O IDENTIFY In Out ============================================================================== Key: In = Target to initiator, Out = Initiator to target. 5.5. Messages. Th singl byt message (Tabl 5-2 ar liste alon wit thei cod value an thei definitions. COMMAN COMPLET 00H (Mandatory). Thi messag i sen fro targe t a initiato t indicat tha th executio o comman (o serie o linke commands ha terminate an tha vali statu ha bee sen t th initiator Afte successfull sendin thi message th targe shal g t th BU FRE phas b releasin BSY. NOTE Th comman ma hav bee execute successfull o unsuccessfull a indicate i th status. EXTENDE MESSAG 01H (Optional). Thi messag i sen fro eithe th initiato o th targe a th firs byt o multiple-byt message (Se 5.5. fo description o extende messages.) SAV DAT POINTE 02H (Optional). Thi messag i sen fro targe t direc th initiato t sav cop o th presen activ dat pointe fo th currentl attache logica unit (Se 5. fo definitio o pointers.) RESTOR POINTER 03H (Optional). Thi messag i sen fro targe t direc th initiato t restor th mos recentl save pointer (fo th currentl attache logica unit t th activ state Pointer t th command data an statu location fo th logica uni shal b restore t th activ pointers Comman an statu pointer shal b restore t th beginnin o th presen comman an statu areas Th dat pointe shal b restore t th valu a th beginnin o th dat are i th absenc o SAV DAT POINTE messag o t th valu a th poin a whic th las SAV DAT POINTE messag occurre fo tha logica unit. DISCONNEC 04H (Optional). Thi messag i sen fro targe t infor a initiato tha th presen physica pat i goin t b broke (th targe plan t disconnec b releasin BSY) bu tha late reconnec wil b require i orde t complet th curren operation I th initiato detect th BU FRE phas (othe tha a resul o RESE condition withou firs receivin DISCONNEC o COMMAN COMPLET message th initiato shal conside thi a catastrophi erro condition I th targe intentionall create thi condition th targe shal clea th curren command Thi messag shal no caus th initiato t sav th dat pointer Note I DISCONNEC message ar use brea lon dat transfe int tw o mor shorte transfers the SAV DAT POINTE shoul b issue befor eac DISCONNEC message. INITIATO DETECTE ERRO 05H (Optional). Thi messag i sen fro a initiato t infor targe tha a erro (e.g. parit error ha occurre tha doe no preclud th targe fro retryin th operation Althoug presen pointe integrit i no assured RESTOR POINTER messag o disconnec followe b reconnect shal caus th pointer t b restore t thei define prio state. ABOR 06H (Optional). Thi messag i sen fro th initiato t th targe t clea th presen operation I logica uni ha bee identified al pendin dat an statu fo th issuin initiato fro th effecte logica uni shal b cleared an th targe shal g t th BU FRE phase Pendin dat an statu fo othe initiator shal no b cleared I logica uni ha no bee identified th targe shal g t th BU FRE phase N statu o endin messag shal b sen fo th operation I i no a erro t issu thi messag t a logica uni tha i no currentl performin a operatio fo th initiator. MESSAG REJEC 07H (Optional). Thi messag i sen fro eithe th initiato o targe t indicat tha th las messag i receive wa inappropriat o ha no bee implemented. I orde t indicat it intention o sendin thi message th initiato shal asser th AT signa prio t it releas o AC fo th REQ/AC handshak o th messag tha i t b rejected Whe targe send thi message i shal chang t MESSAG I phas an sen thi messag prio t requestin additiona messag byte fro th initiator Thi provide a interloc s tha th initiato ca determin whic messag i rejected. Thi messag shal b implemente i an othe optiona message ar implemented N OPERATIO 08H (Optional). Thi messag i sen fro a initiato i respons t target' reques fo messag whe th initiato doe no currentl hav an othe vali messag t send. MESSAG PARIT ERRO 09H (Optional). Thi messag i sen fro th initiato t th targe t indicat tha on o mor byte i th las messag i receive ha parit error. I orde t indicat it intention o sendin thi message th initiato shal asser th AT signa prio t it releas o AC fo th REQ/AC handshak o th messag tha ha th parit error Thi provide a interloc s tha th targe ca determin whic messag ha th parit error. LINKE COMMAN COMPLET 0AH (Optional). Thi messag i sen fro targe t a initiato t indicat tha th executio o linke comman ha complete an tha statu ha bee sent Th initiato shal the se th pointer t th initia stat fo th nex linke command. LINKE COMMAN COMPLET (WIT FLAG 0BH (Optional). Thi messag i sen fro targe t a initiato t indicat tha th executio o linke comman (wit th fla bi se t one ha complete an tha statu ha bee sent Th initiato shal the se th pointer t th initia stat o th nex linke command Typicall thi messag woul b use t caus a interrup i th initiato betwee tw linke commands. BU DEVIC RESE 0CH (Optional). Thi messag i sen fro a initiato t direc targe t clea al curren command o tha SCS device Thi messag force th SCS devic t a initia stat wit n operation pendin fo an initiator Upo recognizin thi message th targe shal g t th BU FRE phase. Reserved 0DH t 7FH. Thes messag code ar reserved fo futur standardization. IDENTIF 80H t FFH (Optional). Thes message ar sen b eithe th initiato o th targe t establis th physica pat connectio betwee a initiato an targe fo particula logica unit. Bi 7. Thi bi i alway se t on t distinguis thes message fro th othe messages. Bi 6. Thi bi i onl se t on b th initiator Whe se t one i indicate tha th initiato ha th abilit t accommodat disconnectio an reconnection. Bit 5-. Reserved. Bit 2-. Thes bit specif a logical unit number in a target. Onl on logica uni numbe shal b identifie fo an on selectio sequence secon IDENTIF messag wit ne logica uni numbe shal no b issue befor th bu ha bee release (BU FRE phase). Whe sen fro targe t a initiato durin reconnection a implie RESTOR POINTER messag shal b performe b th initiato prio t completio o thi message. 5.5. Extende Message (Optional). valu o on i th firs byt o messag indicate th beginnin o multiple-byt extende message Th minimu numbe o byte sen fo a extende messag i three Th extende messag forma an th extende messag code ar show i Table 5- an 5-4 respectively. Table 5-3 Extended Message Format ============================================================================== Byte | Value | Description | ============================================================================== 0 | 01H | Extended message | ----------|----------|-------------------------------------------------------| 1 | nH | Extended message length | ----------|----------|-------------------------------------------------------| 2 | yH | Extended message code | ----------|----------|-------------------------------------------------------| 3 _ nH+1 | xH | Extended message arguments | ============================================================================== Th extende messag lengt specifie th lengt i byte o th extende messag cod plu th extende messag argument t follow Therefore th tota lengt o th messag i equa t th extende messag lengt plu two valu o zer fo th extende messag lengt indicate 25 byte follow. Th extende messag code ar liste i Tabl 5-4 Th extende messag argument ar specifie fo th define extende message i Section 5.5. through 5.5.6. Table 5-4 Extended Message Codes ============================================================================== Code (yH) Description ------------------------------------------------------------------------------ 00H MODIFY DATA POINTER (Optional) 01H SYNCHRONOUS DATA TRANSFER REQUEST (Optional) 02H EXTENDED IDENTIFY (Optional) 03H _ 7FH Reserved 80H _ FFH Vendor Unique ============================================================================== .pa 5.5. MODIF DAT POINTE Messag (Optional) Table 5-5 MODIFY DATA POINTER ============================================================================== Byte | Value | Description | ============================================================================== 0 | 01H | Extended message | -----|---------|-------------------------------------------------------------| 1 | 05H | Extended message length | -----|---------|-------------------------------------------------------------| 2 | 00H | MODIFY DATA POINTER code | -----|---------|-------------------------------------------------------------| 3 | xH | Argument (MSB) | -----|---------|-------------------------------------------------------------| 4 | xH | Argument | -----|---------|-------------------------------------------------------------| 5 | xH | Argument | -----|---------|-------------------------------------------------------------| 6 | xH | Argument (LSB) | ============================================================================== Th MODIF DAT POINTE messag (Tabl 5-5 i sen fro th targe t th initiato an request tha th signe argumen b adde (two' complement t th valu o th current dat pointer. 5.5.5 SYNCHRONOUS DATA TRANSFER REQUEST Message (Optional) Table 5-6 SYNCHRONOUS DATA TRANSFER REQUEST ============================================================================== Byte | Value | Description | ============================================================================== 0 | 01H | Extended message | -----|---------|-------------------------------------------------------------| 1 | 03H | Extended message length | -----|---------|-------------------------------------------------------------| 2 | 01H | SYNCHRONOUS DATA TRANSFER REQUEST code | -----|---------|-------------------------------------------------------------| 3 | mH | Transfer period (mH times 4 nanoseconds) | -----|---------|-------------------------------------------------------------| 4 | xH | REQ/ACK offset | ============================================================================== pai o SYNCHRONOU DAT TRANSFE REQUES message (Tabl 5-6 ar exchange betwee a initiato an targe wheneve a SCS devic tha ca suppor synchronou dat transfe recognize tha i ha no communicate wit th othe SCS devic sinc receivin th las "hard RESE conditio o BU DEVIC RESE message Th SCS device ma als exchang message t establis synchronou dat transfe whe requeste t d so Th messag exchang establishe th transfe perio an th REQ/AC offset Th transfe perio i th minimu tim betwee leadin edge o successiv RE pulse an o successiv AC pulses Th REQ/AC offse i th maximu numbe o RE pulse tha ma b outstandin befor it correspondin AC puls i receive a th target REQ/AC offse valu o zer shal indicat asynchronou mode valu o FFH shal indicat unlimite offset. I th initiato recognize tha negotiatio i required i assert AT and i th targe implement messag transfers send SYNCHRONOU DAT TRANSFE REQUES messag indicatin a REQ/AC offse an minimu transfe period Th REQ/AC offse i chose t preven initiato buffe overflows whil th minimu transfe perio i chose t mee th dat handlin requirement o th initiator Th targe respond i an o th followin ways: Target Response Implied Agreement ------------------------------------- -------------------------------------- (1) REQ/ACK offse less than or equal REQ/ACK offse equal to target value. to the requested value. Minimum transfer period equal to Minimum transfer period equal to or greater than requested period. the target value. (2) REQ/ACK offse equal to zero. Asynchronous transfer. (3) MESSAGE REJECT. Asynchronous transfer. I th targe recognize tha negotiatio i required i send SYNCHRONOU DAT TRANSFE REQUES messag t th initiator Th REQ/AC offse i selecte t preven buffe an offse counte overflows whil th minimu transfe perio i chose t mee th dat handlin requirement o th target Th initiato respond i an o th followin way i th targe choose a REQ/AC offse equa t FFH: Initiator Response Implied Agreement ------------------------------------- -------------------------------------- (1) REQ/ACK offse equa t FFH. REQ/ACK offse unlimited. Minimum transfer period equal to Minimu transfe perio equa to or greater than requested period. the initiator value. (2) REQ/ACK offset equal to 00H. Asynchronou transfer Th target ma renegotiat fo a REQ/ACK offse les tha FFH an greate tha 00H. (3) MESSAGE REJECT. Asynchronous transfer. Th initiato respond i an o th followin way i th targe select a REQ/AC offse les tha FFH: Initiator Response Implied Agreement ------------------------------------- -------------------------------------- (1) REQ/ACK offse less than or equal REQ/ACK offseequals initiator value. to the requested value. Minimum transfer period equal to Minimum transfer period equal to the or greater than requested value. initiator value. (2) REQ/ACK offse equal to zero. Asynchronous transfer. (3) MESSAGE REJECT. Asynchronous transfer. Th implie agreemen shal remai i effec unti BU DEVIC RESE messag i received unti "hard RESE conditio occurs o unti on o th tw SCS device elect t modif th agreement Renegotiatio a ever selectio i no recommended sinc significan performanc impac i likely Th defaul mod o dat transfe i asynchronou mode Th defaul mod i entere a powe on afte BU DEVIC RESE message o afte "hard RESE condition Th SYNCHRONOU DAT TRANSFE REQUES messag exchang ca onl tak plac followin SELECTIO phas tha include th SCS ID fo bot th initiato an th target Violatio o thi rul ma mak dat transfe impossibl owin t disagreement amon SCS device abou th dat transfe mode. 5.5.6 EXTENDED IDENTIFY Message (Optional) Table 5-7 EXTENDED IDENTIFY ============================================================================== Byte | Value | Description | ============================================================================== 0 | 01H | Extended message | -----|---------|-------------------------------------------------------------| 1 | 02H | Extended message length | -----|---------|-------------------------------------------------------------| 2 | 02H | EXTENDED IDENTIFY code | -----|---------|-------------------------------------------------------------| 3 | xxH | Sub-logical unit number | ============================================================================== Th EXTENDE IDENTIF messag (Tabl 5-7 i optiona an ma b sen b targe o a initiator I ma b use i conjunctio wit th norma IDENTIF messag i orde t expan th logica uni numbe addressin i target Th sub-logica uni numbe specifie th encode eight-bi sub- logica uni numbe use t identif on o 25 sub-logica unit withi th logica unit Thi allow u t 204 unit t b addresse o singl target. .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 6 # 6. SCSI Commands  This section defines the SCSI command structure and gives several examples. Th comman definition assum dat structur providin th appearanc a th interfac o contiguou se o logica block o fixe o explicitl define dat length Th SCS devic map th physica characteristic o th attache periphera device t on o severa logica structure define b th devic typ code. singl comman ma transfe on o mor logica block o data Multipl command ma b linke i the ar sen t th sam logica unit targe ma disconnec fro th SCS bu t allo activit b othe SCS device whil logica uni i bein prepare t transfe data Upo comman completio (successfu o unsuccessful) th targe return statu byt t th initiator Sinc mos erro an exceptio condition canno b adequatel describe wit singl statu byte on statu cod, CHEC CONDITION, indicate tha additiona informatio i available Th initiato ma issu REQUES SENS comman t retriev thi additiona information B keepin t minimu th function essentia t communicat vi thi protocol wid rang o periphera device o varyin capabilit ca operat i th sam environment. Becaus subset o th ful architectur ma b implemented optiona function ar noted. 6. Comman Implementatio Requirements. Th firs byt o an SCS comman shal contai a operatio cod a define i thi document Thre bit (bit - 5 o th secon byt o eac SCS comman specif th logica uni i i i no specifie usin th IDENTIF messag (se 5.5.2) Th las byt o al SCS command shal contai contro byt a define i 6.2.6. 6.1. Reserved. Reserve bits fields bytes an cod value ar se asid fo futur standardization Thei us an interpretatio wil b specifie b futur extension t thi standard reserve bit field o byt shal b se t zer, o i accordanc wit futur extensio t thi standard targe tha receive reserve bit field o byt tha i no zer o receive reserve cod valu shal terminat th comman wit CHEC CONDITIO statu and i extende sens i implemented th sens ke shal b se t ILLEGA REQUEST I shal als b acceptabl fo targe t interpre th bit field byte o cod valu i accordanc wit futur extensio t thi standard. 6.1. Operatio Cod Types Operation Code Type Description --------- ------------------------------------------------------------------- M Mandator - Command s designate shal b implemente i orde t mee th minimu requiremen o thi standard. E Extende - Command s designate shal b implemente i additio t mandator command t mee th extende requiremen o thi standard. O Optiona - Command s designated i implemented shal b implemente a define i thi standard. V Vendo uniqu - Operatio code s designate ar availabl fo vendo define commands Se th vendo specification wher compatibilit i desired. R Reserve - Operatio code s designate shal no b used The ar reserve fo futur extension t thi standard. 6.1. Uni Attentio Condition. uni attentio conditio fo logica uni shal begi fo eac initiato wheneve th removabl mediu ma hav bee change o th targe ha bee rese (b BU DEVIC RESE messag o "hard RESE condition) Th uni attentio conditio shal persis fo eac initiato unti tha initiato issue comman t th logica uni othe tha REQUES SENS o INQUIR fo whic th targe shal retur CHEC CONDITIO status I th nex comman fro tha initiato t th logica uni (followin th CHEC CONDITIO status i REQUES SENSE an i th targe support extende sense the th UNI ATTENTIO sens ke shal b returned (I an comman othe tha REQUES SENS i received th uni attentio conditio i lost. .fo Section 6 50.1 I a INQUIR comman i receive fro a initiato wit pendin uni attentio conditio (befor th targe report CHEC CONDITIO status) th targe shal perfor th INQUIR comman an shal no clea th uni attentio condition. I REQUES SENS comman i receive fro a initiato wit pendin uni attentio conditio (befor th targe report CHEC CONDITIO status) the th targe ma either: (1) report any pending sense data and preserve the unit attention condition (2 discar an pendin sens data repor UNI ATTENTIO sens key an clear the unit attention condition for that initiator. I a initiato issue comman othe tha INQUIR o REQUES SENS whil uni attentio conditio exist fo tha initiator th targe shal no perfor th comman an shal repor CHEC CONDITIO status. 6. Comman Descripto Block. reques t periphera devic i performe b sendin comman descripto bloc t th target Fo severa commands th reques i accompanie b lis o parameter sen durin th DAT OU phase Se th specifi command fo detaile information. Th comman descripto bloc alway ha a operatio cod a th firs byt o th command Thi i followe b logica uni number comman parameter (i any) an contro byte. Fo al commands i ther i a invali paramete i th comman descripto block the th targe shal terminat th comman withou alterin th medium. 6.2. Operatio Code. Th operatio cod (Tabl 6-1 o th comman descripto bloc ha grou cod fiel an comman cod field Th three-bi grou cod fiel provide fo eigh group o comman codes Th five-bi comman cod fiel provide fo thirty-tw comman code i eac group Thus tota o 25 possibl operatio code exist Operatio code ar define i Section throug 13. Th grou cod specifies one of the following groups: Group 0 - six-byte commands (see Table 6-2) Group 1 - ten-byte commands (see Table 6-3) Group 2 - reserved Group 3 - reserved Group 4 - reserved Grou - twelve-byt commands (see Table 6-4) Group 6 - vendor unique Group 7 - vendor unique .pa .fo Section 6 50.2 (This page is intentionally blank.) .pa .pn 51 .fo Section 6 # Table 6-1 Operation Code ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Group Code | Command Code | ============================================================================== Table 6-2 Typical Command Descriptor Block for Six-byte Commands ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (if required) (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (if required) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (if required) (LSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length (if required) | -----|-----------------------------------------------------------------------| 5 | Control Byte | ============================================================================== .pa Table 6-3 Typical Command Descriptor Block for Ten-byte Commands ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (if required) (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (if required) | -----|-----------------------------------------------------------------------| 4 | Logical Block Address (if required) | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (if required) (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (if required) (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (if required) (LSB) | -----|-----------------------------------------------------------------------| 9 | Control Byte | ============================================================================== .pa Table 6-4 Typical Command Descriptor Block for Twelve-byte Commands ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (if required) (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (if required) | -----|-----------------------------------------------------------------------| 4 | Logical Block Address (if required) | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (if required) (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Reserved | -----|-----------------------------------------------------------------------| 8 | Reserved | -----|-----------------------------------------------------------------------| 9 | Transfer Length (if required) (MSB) | -----|-----------------------------------------------------------------------| 10 | Transfer Length (if required) (LSB) | -----|-----------------------------------------------------------------------| 11 | Control Byte | ============================================================================== 6.2. Logica Uni Number. Th logica uni numbe addresse on o u t eigh physica o virtua device attache t target Thi metho o addressin i provide fo system tha d no implemen th IDENTIF message targe tha accept a IDENTIF messag shal us th logica uni numbe specifie withi th message I thi case th targe shal ignor th logica uni numbe specifie withi th comman descripto block (Implementor note I i goo practic fo initiator tha implemen th IDENTIF messag t specif th sam logica uni numbe i th comman descripto block.) 6.2. Logica Bloc Address. Th logica bloc addres o logica unit shal begi wit bloc zer an b contiguou u t th las logica bloc o tha logica unit. Grou comman descripto block contai 21-bi logica bloc addresses Group an comman descripto block contai 32-bi logica bloc addresses. Th logica bloc concep implie tha th initiato an targe shal hav previousl establishe th numbe o dat byte pe logica block Thi ma b establishe throug th us o th REA CAPACIT comman o th MOD SENS comman o b prio arrangement. .pa 6.2. Relativ Addres Bit. Th relativ addres (RelAdr bi o th group an grou command i se t on t indicat tha th logica bloc addres portio o th comman descripto bloc i two' complemen displacement Thi negativ o positiv displacemen i t b adde t th logica bloc addres las accesse o th logica uni t for th logica bloc addres fo thi command Thi featur i onl availabl whe linkin commands Th featur require tha previou comman i th linke grou hav accesse bloc o dat o th logica unit (Fo a exampl o th operatio o thi function se Sectio 6.3.3.) 6.2. Transfe Length. Th transfe lengt specifie th amoun o dat t b transferred usuall th numbe o blocks Fo severa command th transfe lengt indicate th requeste numbe o byte t b sen a define i th comman description Fo thes command th transfe lengt fiel ma b identifie b differen name Se th followin description an th individua comman description fo furthe information. Command tha us on byt fo transfe lengt allo u t 25 block o dat t b transferre b on command transfe lengt valu o t 25 indicate th numbe o block tha shal transferred valu o zer indicate 25 blocks. Command tha us tw byte fo transfe lengt allo u t 65,53 block o dat t b transferre b on command I thi case transfe lengt o zer indicate tha n dat transfe shal tak place valu o t 65,53 indicate th numbe o block tha shal b transferred Fo severa command mor tha tw byte ar allocate fo transfe length Refe t th specifi comman descriptio fo furthe information. Th transfe lengt o th command tha ar use t sen lis o parameter t targe i calle th paramete lis length Th paramete lis lengt specifie th numbe o byte sen durin th DAT OU phase. Th transfe lengt o th command tha ar use t retur sens dat (e.g REQUES SENSE INQUIRY MOD SENSE etc t a initiato i calle th allocatio length Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo returne data Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl sens dat hav bee transferre t th initiator whicheve i less. 6.2. Contro Byte. Th contro byt i th las byt o ever comman descripto block typica contro byt i describe i Tabl 6-5. .pa Table 6-5 Control Byte ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== Last | Vendor unique | Reserved | Flag | Link | ============================================================================== Bit Description ----- ---------------------------------------------------------------------- 7 _ 6 Vendor unique 5 _ 2 Reserved 1 Fla bi - I th lin bi i zero the th fla bi shal b se t zero I th lin bi i one an i th comman terminate successfully th targe shal sen LINKE COMMAN COMPLET messag i th fla bi i zer an shal sen LINKE COMMAN COMPLET (WIT FLAG messag i th fla bi i one Typically thi bi i use t caus a interrup i th initiato betwee linke commands. 0 Lin bi - Thi bi i se t on t indicat tha th initiato desire a automati lin t th nex comman upo successfu completio o th curren command Implementatio o linke command i optional I th lin bi i one target that implemen linke commands upo successfu terminatio o th command shal retur INTERMEDIAT statu an shal the sen on o th tw message define b th fla bi (above). Target that d no implemen linke command shal retur a CHEC CONDITIO statu and i extende sens i implemented shal se th sens ke t ILLEGA REQUES i eithe o th lin an fla bit ar se t one. 6.3 Command Examples 6.3. Singl Comman Example. typica operatio o th SCS bu i likel t includ singl REA comman t periphera device Thi operatio i describe i detai startin wit reques fro th initiator Thi exampl assume tha n linke command an n malfunction o error occur. Th initiato ha activ pointer an se o store pointer representin activ disconnecte SCS device (a initiato withou disconnec capabilit doe no requir store pointers) Th initiato set u th activ pointer fo th operatio requested arbitrate fo th SCS bus an select th target Onc thi proces i completed th targe assume contro o th operation. Th targe obtain th comman fro th initiato (i thi cas, REA command) Th targe interpret th comman an execute it I thi case th targe get th dat fro th periphera devic an send i t th initiator A th completio o th REA command th targe send statu byt t th initiator T en th operation th targe send COMMAN COMPLET messag t th initiator. 6.3. Disconnec Example. I th abov singl comman example th lengt o tim necessar t obtai th dat ma requir time-consumin physica seek I orde t improv syste throughput th targe ma disconnec fro th initiator freein th SCS bu t allo othe request t b sen t othe logica units T d this th initiato need t b reselectabl an capabl o restorin th pointer upo reconnection Th targe need t b capabl o arbitratin fo th SCS bu an reselectin th initiator. Afte th targe ha receive th REA comman (an ha determine tha ther wil b delay) i disconnect b sendin DISCONNEC messag an releasin BSY. Whe th dat ar read t b transferred th targe reconnect t th initiator A resul o thi reconnection th initiato restore th pointer t thei mos recen save value (which i thi case ar th initia values an th targe continue (a i th singl comman example t finis th operation Th initiato recognize tha th operatio i complet whe COMMAN COMPLET messag i received. I targe wishe t disconnec afte transferrin par o th dat (e.g. whil crossin cylinde boundary) i ma d s b sendin SAV DAT POINTE messag an DISCONNEC messag t th initiato an the disconnecting Whe reconnectio i completed th curren dat pointe valu i restore t it valu immediatel prio t th SAV DAT POINTE message. O thos occasion whe a erro o exceptio conditio occur an th targe elect t repea th informatio transfer th targe ma repea th transfe b eithe issuin RESTOR POINTER messag o b disconnectin withou issuin SAV DAT POINTE message Whe reconnectio i completed th mos recen save pointe value ar restored. 6.3. Linke Comman Example. Th lin functio define relationshi betwee command tha whe combine wit th relativ addres bit allow previou operation t modif subsequen operations Lin make high- performanc function possibl b providin relativ addressin capabilit an allowin multipl comman executio withou invokin th functiona componen o th initiator. I th desire dat addres (i th previousl describe REA comman example i unknown bu searc ke define a som particula byte o fiel i known the b linkin th REA comman t SEARC DAT EQUA command th dat ca b quickl an effectivel transferre t th initiator LINKE COMMAN COMPLET messag i sen fro th targe t th initiato t indicat linke comman completion Th initiato the update th store pointer s tha subsequen request fro th targe wil referenc th nex comman o th chain Comman processin o linke an singl command i simula excep tha relativ addressin i permitte i linke commands Linke command shal b addresse t singl logica unit. Fo example th successfu completio o SEARC DAT EQUA comman cause th targe t fetc th linke REA comman fro th initiator I th relativ addres bi i th REA comman ha bee se t one an th addres fiel o th REA comman i se t zero th targe transfer th successfull searche bloc t th initiator .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 7 # 7. Command Descriptions for All Device Types 7. Grou Command fo Al Devic Types. Thes command shal b a liste i Tabl 7-1. Table 7-1 Group 0 Common Commands for All Device Types ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H TES UNI READ 7.1.1 01H * 02H V 03H M REQUEST SENSE 7.1.2 04H * 05H * 06H V 07H * 08H * 09H V 0AH * 0BH * 0CH V 0DH V 0EH V 0FH * 10H * 11H * 12H E INQUIRY 7.1.3 13H * 14H * 15H * 16H * 17H * 18H O COPY 7.1.4 19H * 1AH * 1BH * 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH * 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. * = Thes operatio code ma hav differen meaning fo specifi type o periphera devices (Se th appropriat sectio fo furthe information.) .pa 7.1.1 TEST UNIT READY Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 00H Table 7-2 TEST UNIT READY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th TES UNI READ comman (Tabl 7-2 provide mean t chec i th logica uni i ready Thi i no reques fo sel test I th logica uni woul accep a appropriat medium-acces comman withou returnin CHEC CONDITIO status this comman shal return GOO status 7.1.2 REQUEST SENSE Command Peripheral Device Type: All Operation Code Type: Mandatory Operation Code: 03H Table 7-3 REQUEST SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REQUES SENS comman (Tabl 7-3 request tha th targe transfe sens dat t th initiator. Th sens dat shal b vali fo CHEC CONDITIO statu returne o th prio command Thi sens dat shal b preserve b th targe fo th initiato unti retrieve b th REQUES SENS comman o unti th receip o an othe comman fo th sam logica uni fro th initiato tha issue th comman resultin i th CHEC CONDITIO status Sens dat shal b cleare upo receip o an subsequen comman t th logica uni fro th initiato receivin th CHEC CONDITIO status I th cas o th singl initiato optio (se 5.1.3.4) th targe shal assum tha th REQUES SENS comman i fro th sam initiator. Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo returne sens data A allocatio lengt o zer indicate tha fou byte o sens dat shal b transferred An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl sens dat hav bee transferre t th initiator whicheve i less. Th REQUES SENS comman shal retur th CHEC CONDITIO statu onl t repor fata error fo the REQUEST SENSE command Fo example: (1 Th targe receive nonzer reserve bi i th comman descripto block. (2) An unrecovered parity error occurs on the DATA BUS. (3) A target malfunction prevents return of the sense data. I an nonfata error occus durin th executio o th REQUES SENS command th targe shal retur th sens dat wit GOO status. Followin fata erro o REQUES SENS command sens dat ma b invalid targe ma implemen th nonextended th extended o bot sens dat formats (Implementor note Target tha implemen bot sens dat format ma selec th nonextende sens dat forma i respons t a allocatio lengt o zero Othe method o selectio ar als feasible.) 7.1.2. Nonextende Sense. Th forma o th sens dat i determine b th erro class Erro classe throug us th nonextende sens dat forma (Tabl 7-4) Erro clas i describe i Sectio 7.1.2.2. .pa Table 7-4 Nonextended Sense Data Format ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | AdValid| Error Class | Error Code | -----|-----------------------------------------------------------------------| 1 | Vendor Unique |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | ============================================================================== Th addres vali (AdValid bi indicate tha th logica bloc addres fiel contain vali informatio relate t th erro code. Th erro clas specifie clas o error wit erro classe throug bein vendo unique For these classes, th erro cod is vendo uniqu. 7.1.2. Extende Sense. Erro clas specifie extende sense Erro cod zer specifie th extende sens dat format Erro cod FH specifie vendo uniqu dat forma fo extende sense Erro code 1H throug EH ar reserved. The extended sense data format is shown in Table 7-5. Table 7-5 Extended Sense Data Format ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Valid | Error Class (7) | Error Code (0) | -----|-----------------------------------------------------------------------| 1 | Segment Number | -----|-----------------------------------------------------------------------| 2 |Filemark| EOM | ILI |Reserved| Sense Key | -----|-----------------------------------------------------------------------| 3 | Information Byte (MSB) | -----|-----------------------------------------------------------------------| 4 | Information Byte | -----|-----------------------------------------------------------------------| 5 | Information Byte | -----|-----------------------------------------------------------------------| 6 | Information Byte (LSB) | -----|-----------------------------------------------------------------------| 7 | Additional Sense Length (n) | -----|-----------------------------------------------------------------------| 8 _ | Additional Sense Bytes | n+7 | | ============================================================================== Th informatio byte ar no define i th vali bi i zero I th vali bi i one th informatio byte contai vali informatio a follows: (1 Th unsigne logica bloc addres associate wit th sens key fo direct-acces device (Typ 0) write-onc read-multipl device (Typ 4) an read-onl direct-acces device (Typ 5). (2 Th differenc (residue o th requeste lengt minus th actua lengt i eithe byte o blocks a determine b th command, fo sequential-acces device (Typ 1) printe device (Typ 2) an processo device (Typ 3) (Negativ value ar indicate b two' complemen notation.) (3 Th differenc (residue o th requeste numbe o block minus the actua numbe o block copie o compare fo th curren segmen descripto of a COPY, COMPARE, or COPY AND VERIFY command. Th segmen numbe contain th numbe o th curren segmen descripto i th extende sens i i respons t COPY COMPARE o COP AN VERIF command U t 25 segment ar supporte beginnin wit segmen zero. Th filemar bi indicate tha th curren comman ha rea filemark Thi bi i onl use fo sequential-acces devices. Th end-of-mediu (EOM bi indicate tha a end-of-mediu conditio (end- of-tape beginning-of-tape out-of-paper etc exist o sequentia acces devic o printe device Fo sequential-acces devices thi bi indicate tha th uni i a o pas th early-warnin end-of-tap i th directio wa forwar o tha th comman coul no b complete becaus beginning-of-tap wa encountere i th directio wa reverse Direct-acces device shal no us thi bit instead thes device shal repor attempt t acces beyon th end-of-mediu a ILLEGA REQUES sens ke (se Tabl 7-6). Th incorrec lengt indicato (ILI bi indicate tha th requeste logica bloc lengt di no matc th logica bloc lengt o th dat o th medium. The sense keys are described in Tables 7-6 and 7-7. Th additiona sens lengt specifie th numbe o additiona sens byte t follow I th allocatio lengt o th comman descripto bloc i to smal t transfe al o th additiona sens bytes th additiona sens lengt i no adjuste t reflec th truncation. Th additiona sens byte contai command-specific peripheral-device- specifi data o bot kind o dat tha furthe defin th natur o th CHEC CONDITIO status Th COPY COMPARE COP AN VERIFY an SEARC DAT command defin standar purpos fo som o thes bytes Excep a describe i thes commands th additiona sens byte ar vendo unique. .pa Table 7-6 Sens Ke (0H-7H) Descriptions ============================================================================== Sense Key Description --------- ------------------------------------------------------------------- 0H N SENSE Indicate tha ther i n specifi sens ke informatio t b reporte fo th designate logica unit Thi woul b th cas fo successfu comman o comman tha receive CHEC CONDITIO statu becaus on o th filemark EO, o IL bit i se t one. 1H RECOVERE ERROR Indicate tha th las comman complete successfull wit som recover actio performe b th target Detail ma b determinabl b examinin th additiona sens byte an th informatio bytes. 2H NO READY Indicate tha th logica uni addresse canno b accessed Operato interventio ma b require t correc thi condition. 3H MEDIU ERROR Indicate tha th comman terminate wit nonrecovere erro conditio tha wa probabl cause b fla i th mediu o a erro i th recorde data. 4H HARDWAR ERROR Indicate tha th targe detecte nonrecoverabl hardwar failur (fo example controlle failure devic failure parit error etc whil performin th comman o durin sel test. 5H ILLEGA REQUEST Indicate tha ther wa a illega paramete i th comman descripto bloc o i th additiona parameter supplie a dat fo som command (FORMA UNIT SEARC DATA etc) I th targe detect a invali paramete i th comman descripto block the i shal terminat th comman withou alterin th medium I th targe detect a invali paramete i th additiona parameter supplie a data the th targe ma hav alread altere th medium. 6H UNI ATTENTION Indicate tha th removabl mediu ma hav bee change o th targe ha bee reset Se 6.1. fo mor detaile information about the unit attention condition. 7H DAT PROTECT Indicate tha comman tha read o write th mediu wa attempte o bloc tha i protecte fro thi operation Th rea o writ operatio i no performed. ============================================================================== .pa Table 7-7 Sens Ke (8H-FH) Descriptions ============================================================================== Sense Key Description --------- ------------------------------------------------------------------- 8H BLAN CHECK Indicate tha write-onc read-multipl devic o sequential-acces devic encountere blan bloc whil readin o write-onc read-multipl devic encountere nonblan bloc whil writing. 9H Vendo unique Thi sens ke i availabl fo reportin vendo uniqu conditions. AH COP ABORTED Indicate COPY COMPARE o COP AN VERIF comman wa aborte du t a erro conditio o th sourc device th destinatio device o both (Se 7.1..2 fo additiona information about this sense key.) BH ABORTE COMMAND Indicate tha th targe aborte th command Th initiato ma b abl t recove b tryin th comman again. CH EQUAL Indicate SEARC DAT comman ha satisfie a equa comparison. DH VOLUM OVERFLOW Indicate tha buffere periphera devic ha reache th end-of-mediu an dat remain i th buffe tha ha no bee writte t th medium RECOVE BUFFERE DAT command(s ma b issue t rea th unwritte dat fro th buffer. EH MISCOMPARE Indicate tha th sourc dat di no matc th dat rea fro th medium. FH This sense key is reserved. ============================================================================== .pa 7.1.3 INQUIRY Command Peripheral Device Type: All Operation Code Type: Extended Operation Code: 12H Table 7-8 INQUIRY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th INQUIR comman (Tabl 7-8 request tha informatio regardin parameter o th targe an it attache periphera device(s b sen t th initiator. Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo returne INQUIRY data A allocatio lengt o zer indicate tha n INQUIRY dat shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl INQUIRY dat have bee transferre t th initiator, whichever is less Th INQUIR comman shal retur CHEC CONDITIO statu onl whe th targe canno retur th requeste INQUIR data (Implementor note I i recommende tha th INQUIR dat b returne eve thoug th periphera devic ma no b read fo othe commands.) I a INQUIR comman i receive fro a initiato wit pendin uni attentio conditio (befor th targe report CHEC CONDITIO status) th targe shal perfor th INQUIR comman an shal no clea th uni attentio condition. (See 6.1.3.) Th INQUIR dat (Tabl 7-9 contain fiv byt header followe b th vendo uniqu parameters i any .pa Table 7-9 INQUIR Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Peripheral Device Type | -----|-----------------------------------------------------------------------| 1 | RMB | Device-Type Qualifier | -----|-----------------------------------------------------------------------| 2 | ISO Version | ECMA Version | ANSI Version | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Additional Length (n) | ============================================================================== | Vendor Unique Parameters | ============================================================================== 5 _ | Vendor Unique | n+4 | Parameter Bytes | ============================================================================== The peripheral device type is shown in Table 7-10. Table 7-10 Peripheral Device Type ============================================================================== Code Description ------------------------------------------------------------------------------ 00H Direct-access device (e.g., magnetic disk) 01H Sequential-access device (e.g., magnetic tape) 02H Printer device 03H Processor device 04H Write-once read-multiple device (e.g., some optical disks) 05H Read-only direct-access device (e.g., some optical disks) 06H _ 7EH Reserved 7FH Logical unit not present 80H _ FFH Vendor unique ============================================================================== removabl mediu (RMB bi o zer indicate tha th mediu i no removable RM bi o on indicate tha th mediu i removable. Th device-typ qualifie i seve bi use specifie code Thi cod ma b se wit switche o b som othe mean b th targe o periphera device SCS device tha d no suppor thi featur shal retur al zer bits Thi featur allow eac use t assig uniqu code t eac specifi typ o periphera devic tha i supporte o th syste bein used Thes code ma the b use b self-configurin softwar t determin wha specifi periphera devic i a eac logica uni number Thi i especiall valuabl fo system tha suppor multipl type o removabl medium. Th usag o nonzer cod value i th IS versio an ECM versio field ar define b th Internationa Standard Organizatio an th Europea Compute Manufacturer Association respectively zer cod valu i thes field shal indicat tha th targe doe no clai complianc t th IS o ECM version o SCSI Not tha i i possibl t clai complianc t mor than one of these SCSI standards. Th ANS versio indicate th implemente versio o thi standar an i define a show i Tabl 7-11. Table 7-11 ANSI Version ============================================================================== Code Description ------------------------------------------------------------------------------ 0H Versio i unspecified (Us thi cod i yo ar implementin to this document - it is not published, yet.) 1H Thi version Thi cod shal b use b SCS device tha clai t compl wit thi standar (upo ANS publication) 2H _ 7H Reserved ============================================================================== Th additiona lengt shal specif th lengt i byte o th vendo uniqu parameters I th allocatio lengt o th comman descripto bloc i to smal t transfe al o th vendo uniqu parameters th additiona lengt shall no be adjuste t reflec th truncation. 7.1.4 COPY Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 18H Table 7-12 COPY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Parameter List Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Parameter List Length | -----|-----------------------------------------------------------------------| 4 | Parameter List Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th COP comman (Tabl 7-12 provide mean t cop dat fro on logica uni t anothe o th sam logica unit Th logica unit ma resid o th sam SCS devic o differen SCS devices Som SCS device tha implemen thi comman ma no suppor copie t o fro anothe SCS devic o thir part copie (bot logica unit resid o othe SCS devices). Th paramete lis lengt specifie th lengt i byte o th parameter tha shal b sen durin th DAT OU phas o th command paramete lis lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error. Th COP paramete lis (Tabl 7-13 begin wit four-byt heade tha contain th COP functio cod an priority Followin th heade i on o mor segmen descriptors Table 7-13 COPY Parameter List ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | COPY Function Code | Priority | -----|-----------------------------------------------------------------------| 1 | Vendor Unique | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | ============================================================================== | Segment Descriptor(s) | ============================================================================== 0 _ | Segment Descriptor 0 | xx | (See specific table for length.) | -----|-----------------------------------------------------------------------| | . | | . | | . | -----|-----------------------------------------------------------------------| 0 _ | Segment Descriptor n | xx | (See specific table for length.) | ============================================================================== Th COP functio cod define specifi forma fo th segmen descriptors Th COP functio code ar define i Tabl 7-14. Th priorit fiel o th COP paramete lis establishe th relativ priorit o thi COP comman t othe command bein execute b th sam target Al othe command ar assume t hav priorit o 1 Priority i th highes priorit wit increasin value indicatin lowe priorities. Th segmen descripto format ar determine b th COP functio code Th segmen descripto forma use fo write-onc read-multipl device an fo read-onl direct-acces device shal b th sam a fo direct-acces devices Th segmen descripto forma use fo printe device an fo processo device shal b th sam a fo sequential-acces devices Thu COP fro write-onc read-multipl devic t printe devic use th sam segmen descripto forma a fo COP fro direct-acces devic t sequential-acces device (Se Tabl 7-14. Th segmen descripto format ar describe i Table 7-15 throug 7-17 maximu o 25 segmen descriptor ar permitted Th segmen descriptor ar identifie b ascendin number beginnin wit zero. Table 7-14 COPY Functions ============================================================================== Peripheral Device Type COPY Segment ---------------------- Function Descriptor Source Destination Code Table Comment ------------------------------------------------------------------------------ 00H 01H 00H Tabl 7-15 00H 02H 00H Tabl 7-15 00H 03H 00H Tabl 7-15 04H 01H 00H Tabl 7-15 Direct Access 04H 02H 00H Tabl 7-15 to 04H 03H 00H Tabl 7-15 Sequential Access 05H 01H 00H Tabl 7-15 05H 02H 00H Tabl 7-15 05H 03H 00H Tabl 7-15 01H 00H 01H Tabl 7-15 Sequential Access 01H 04H 01H Tabl 7-15 to 03H 00H 01H Tabl 7-15 Direct Access 03H 04H 01H Tabl 7-15 00H 00H 02H Tabl 7-16 00H 04H 02H Tabl 7-16 Direct Access 04H 00H 02H Tabl 7-16 to 04H 04H 02H Tabl 7-16 Direct Access 05H 00H 02H Tabl 7-16 05H 04H 02H Tabl 7-16 01H 01H 03H Tabl 7-17 01H 02H 03H Tabl 7-17 Sequential Access 01H 03H 03H Tabl 7-17 to 03H 01H 03H Tabl 7-17 Sequential Access 03H 02H 03H Tabl 7-17 03H 03H 03H Tabl 7-17 ============================================================================== Periphera devic type 00H Direct-acces device 01H Sequential-acces device 02H Printer device 03H Processor device 04H Write-once read-multiple device 05H Read-only direct-access device COP functio code 00H Direc acces t sequentia access 01H Sequentia acces t direc access 02H Direc acces t direc access 03H Sequentia acces t sequentia access 04H _ 0FH Reserved 10H _ 1FH Vendo unique .pa 7.1.4. Error Detecte b th Managin SCS Device. Tw classe o unusua condition ma occu durin executio o COP command Th firs clas consist o thos unusua condition detecte b th SCS devic tha receive th COP comman an i managin th executio o th command Thes condition includ parit error whil transferrin th COP comman an statu byte invali parameter i th COP command invali segmen descriptors an inabilit o th SCS devic controllin th COP function t continu operating I th even o suc a unusua condition th SCS devic managin th COP shall: (1)Terminate the COPY command with a CHECK CONDITION status. (2 Retur th sens dat i th extende sens format Th vali bi shal b se t one Th segmen numbe shal contai th numbe o th segmen descripto bein processe a th tim th unusua conditio i detected Th sens ke shal contai th sens ke cod describin th unusua condition Th informatio byte shal contai th differenc betwee th numbe o block fiel i th segmen descripto bein processe a th tim o th failur an th numbe o block successfull copied Thi numbe i th residu o unprocesse block remainin fo th segmen descriptor. 7.1.4. Error Detecte b Target. Th secon clas o error consist o unusua condition detecte b th SCS devic transferrin dat a th reques o th SCS devic managin th transfer Th SCS devic managin th COP comman detect unusua condition b receivin CHEC CONDITIO statu fro on o th SCS device i i managing I the shal recove th sens dat associate wit th unusua condition. Th SCS devic managin th COP comman ma als b th sourc o destinatio SCS devic (o both) I shal distinguis betwee failur o th managemen o th COP an failur o th dat transfe bein requested I shal the creat th appropriat sens dat internally. Afte recoverin th sens dat associate wit th detecte error th SCS devic managin th COP comman shall: (1)Terminate the COPY command with a CHECK CONDITION status. (2 Retur th sens dat i th extende sens format Th vali bi shal b se t one Th segmen numbe shal contai th numbe o th segmen descripto bein processe a th tim th unusua conditio i detected Th sens ke shal b se t COPY ABORTED Th informatio byte shal contai th differenc betwee th numbe o block fiel i th segmen descripto bein processe a th tim o th failur an th numbe o block successfull copied Thi numbe i th residu o unprocesse block remainin fo th segmen descriptor Th additiona sens lengt shal specif th numbe o additiona sens bytes. Th firs additiona sens byt shal specif th byt number relativ t th firs byt o sens dat o th beginnin o th sourc logica unit' statu byt an sens data zer valu indicate tha n statu byt o sens dat i bein returne fo th sourc logica unit Th firs byt o th are pointe t b th firs additiona sens byt shal contai th statu byt fro th sourc logica unit Th subsequen byte shal contain unchanged th sens dat recovere fro th sourc logica unit. Th secon additiona sens byt shal specif th byt number relativ t th firs byt o sens dat o th beginnin o th destinatio logica unit' statu byt an sens data zer valu indicate tha n statu byt o sens dat i bein returne fo th destinatio logica unit Th firs byt o th are pointe t b th secon additiona sens byt shal contai th statu byt fro th destinatio logica unit Th subsequen byte shal contain unchanged th sens dat recovere fro th destinatio logica unit. 7.1.4. COP Functio Cod 00H an 01H. Th forma fo th segmen descriptor fo COP transfer betwee direct-acces an sequential-acces device i specifie i Tabl 7-15 Thi forma i require fo COP functio code 00H o 01H Th segmen descripto ma b repeate u t 25 time withi th paramete lis lengt specifie i th comman descripto block. Table 7-15 Segment Descriptor for COPY Function Codes 00H and 01H ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Source Address | Reserved | Source LUN | -----|-----------------------------------------------------------------------| 1 | Destination Address | Reserved | Destination LUN | -----|-----------------------------------------------------------------------| 2 | Sequential-Access Device Block-Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Sequential-Access Device Block-Length (LSB) | -----|-----------------------------------------------------------------------| 4 | Direct-Access Device Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 5 | Direct-Access Device Number of Blocks | -----|-----------------------------------------------------------------------| 6 | Direct-Access Device Number of Blocks | -----|-----------------------------------------------------------------------| 7 | Direct-Access Device Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 8 | Direct-Access Device Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 9 | Direct-Access Device Logical Block Address | -----|-----------------------------------------------------------------------| 10 | Direct-Access Device Logical Block Address | -----|-----------------------------------------------------------------------| 11 | Direct-Access Device Logical Block Address (LSB) | ============================================================================== Sourc addres an destinatio addres field specif th SCS device an th sourc LU an destinatio LU field specif th logica unit t us fo thi segmen o th COPY command Som SCS device ma no suppor "third- party COPY i whic th copyin SCS devic i no th sourc o destinatio device Som SCS device onl suppor COPY withi th SCS devic an no t othe SCS devices I a unsupporte COPY operatio i requested th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shall be se t ILLEGA REQUEST. Th sequential-acces devic block-lengt fiel specifie th block-lengt t b use o th sequential-acces logica uni durin thi segmen o th COP command I thi block-lengt i know b th SCS devic managin th COPY t b no supported th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t ILLEGA REQUEST I th block-lengt i foun t b invali whil executin rea o writ operatio t th sequential-acces device th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shall be se t COP ABORTED. Th direct-acces devic numbe o block fiel specifie th numbe o block i th curren segment valu o zer indicate tha n block shal b transferre i thi segment Th direct-acces devic logica bloc addres specifie th startin logica bloc addres o th logica uni fo thi segment. 7.1.4. COP Functio Cod 02H. Th forma fo th segmen descriptor fo COP transfer amon direct-acces device i specifie b Tabl 7-16 Thi forma i require fo COP functio cod 02H Th segmen descripto ma b repeate u t 25 time withi th paramete lis lengt specifie i th comman descripto block. .pa Table 7-16 Segment Descriptor for COPY Function Code 02H ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Source Address | Reserved | Source LUN | -----|-----------------------------------------------------------------------| 1 | Destination Address | Reserved | Destination LUN | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Source Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 5 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 6 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 7 | Source Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 8 | Source Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 9 | Source Logical Block Address | -----|-----------------------------------------------------------------------| 10 | Source Logical Block Address | -----|-----------------------------------------------------------------------| 11 | Source Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 12 | Destination Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 13 | Destination Logical Block Address | -----|-----------------------------------------------------------------------| 14 | Destination Logical Block Address | -----|-----------------------------------------------------------------------| 15 | Destination Logical Block Address (LSB) | ============================================================================== Th sourc addres an destinatio addres field specif th SCS device an th sourc LU an destinatio LU specif th logica unit t us fo thi segmen o th COPY command Som SCS device ma no suppor "third- party COPY i whic th copyin SCS devic i no th sourc o destinatio device Som SCS device onl suppor COPY withi th SCS devic an no t othe SCS devices I a unsupporte COPY operatio i requested th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shall be se t ILLEGA REQUEST. Th sourc numbe o block fiel specifie th numbe o block t b transferre fro th sourc devic durin comman execution Th sourc logica bloc addres fiel specifie th startin logica bloc addres o th sourc device Th destinatio logica bloc addres fiel specifie th startin logica bloc addres o th destinatio device. .pa 7.1.4. COP Functio Cod 03H. Th forma fo th segmen descriptor fo COP transfer amon sequential-acces device i specifie b Tabl 7-17 Thi forma i require fo COP functio cod 03H Th segmen descripto ma b repeate u t 25 time withi th paramete lis lengt specifie i th comman descripto block. Table 7-17 Segment Descriptor for COPY Function Code 03H ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Source Address | Reserved | Source LUN | -----|-----------------------------------------------------------------------| 1 | Destination Address | Reserved | Destination LUN | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Source Block Length (MSB) | -----|-----------------------------------------------------------------------| 5 | Source Block Length (LSB) | -----|-----------------------------------------------------------------------| 6 | Destination Block Length (MSB) | -----|-----------------------------------------------------------------------| 7 | Destination Block Length (LSB) | -----|-----------------------------------------------------------------------| 8 | Source Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 9 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 10 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 11 | Source Number of Blocks (LSB) | ============================================================================== Sourc addres an destinatio addres field specif th SCS device an th sourc LU an destinatio LU field specif th logica unit t us fo thi segmen o th COPY command Som SCS device ma no suppor "third- party COPY i whic th copyin SCS devic i no th sourc o destinatio device Som SCS device onl suppor COPY withi th SCS devic an no t othe SCS devices I a unsupporte COPY operatio i requested th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shall be se t ILLEGA REQUEST. Th sourc block-lengt fiel specifie th block-lengt o th sourc devic fo thi segmen o th COPY zer i thi fiel indicate variabl block-length Fo nonzer values thi fiel shal matc th logica unit' actua block-length I block-lengt mismatche ar detecte b th SCS devic managin th COPY th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t ILLEGA REQUEST I th mismatche ar detecte durin th rea operatio b th COP manager th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t COP ABORTED. Th destinatio block-lengt fiel specifie th block-lengt t b use o th destinatio logica uni durin th COPY Destinatio block-lengt mismatche ar handle i th sam manne a sourc block-lengt mismatches. Th sourc numbe o block fiel specifie th numbe o block t b transferre fro th sourc devic durin thi segment valu o zer indicate tha n block shal b transferred. 7.1. RECEIV DIAGNOSTI RESULT Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 1CH Table 7-18 RECEIVE DIAGNOSTIC RESULTS Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Allocation Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Allocation Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RECEIV DIAGNOSTI RESULT comman (Tabl 7-18 request analysi dat b sen t th initiato afte completio o SEN DIAGNOSTI comman (se 7.1.6). Th allocatio lengt shal specif th numbe o byte tha th initiato ha allocate fo returne diagnosti data A allocatio lengt o zer indicate tha n diagnosti dat shal b transferred An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe terminate th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl diagnosti dat hav bee transferre t th initiator, whichever is less The diagnostic data returned is vendor unique. NOTE Althoug diagnosti softwar i generall device-specific thi comman an th SEN DIAGNOSTI comman provid mean t isolat th operatin syste softwar fro th device-specifi diagnosti software Henc th operatin syste ca remai device-independent Thi als allow diagnosti softwar t b mor easil porte t othe operatin systems. .pa 7.1.6 SEN DIAGNOSTI Command Peripheral Device Type: All Operation Code Type: Optional Operatio Code 1DH Table 7-19 SEN DIAGNOSTI Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved |SelfTest| DevOfL | UnitOfL| -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Parameter List Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Parameter List Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SEN DIAGNOSTI comman (Tabl 7-19 request th targe t perfor diagnosti test o itself o th attache periphera devices o o both Thi comman i usuall followe b RECEIV DIAGNOSTI RESULT command excep whe th sel tes (SelfTest bi i on. Th paramete lis lengt specifie th lengt i byte o th paramete lis tha shal b transferre durin th DAT OU phase paramete lis lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error Th paramete lis i vendo unique. logica uni off-lin (UnitOfL bi o on enable writ operation o use mediu o operation tha affec use visibl mediu positioning A SCS devic off-lin (DevOfL bi o on enable diagnosti operation that ma adversel affec operation t othe logica unit o th sam target. Th logica uni off-lin an SCS devic off-lin bit ar generall se b operatin syste software whil th paramete lis i prepare b diagnosti applicatio software Thus b preventin operation that ar no enable b thes bits th targe assist th operatin syste i protectin it resources. sel tes bi o on direct th targe t complet it defaul sel test I th sel tes i requested th paramete lis lengt shal b se t zer an n dat shal b transferred I th sel tes successfull passes th comman shal b terminate wit GOO status otherwise th comman shal b terminate wit CHEC CONDITIO statu and i extende sens i implemented th sens ke shal b se t HARDWAR ERROR. NOTE Se th not unde th RECEIV DIAGNOSTI RESULT comman (7.1.5). .pa 7. Grou Command fo Al Devic Types. Thes command shal b a liste i Tabl 7-20. Table 7-20 Group 1 Commands for All Device Types ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 20H V 21H V 22H V 23H V 24H V 25H * 26H V 27H V 28H * 29H V 2AH * 2BH * 2CH V 2DH V 2EH * 2FH * 30H * 31H * 32H * 33H * 34H R 35H R 36H R 37H R 38H R 39H O COMPARE 7.2.1 3AH O COPY AND VERIFY 7.2.2 3BH R 3CH R 3DH R 3EH R 3FH R ============================================================================== Key: O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. * = Thes operatio code ma hav differen meaning fo specifi type o periphera devices (Se th appropriat sectio fo furthe information.) .pa 7.2.1 COMPARE Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 39H Table 7-21 COMPARE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| Parameter List Length (MSB | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Parameter List Length (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Reserved | -----|-----------------------------------------------------------------------| 8 | Reserved | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th COMPAR comman (Tabl 7-21 provide th mean t compar dat fro on logica uni wit anothe o th sam logica uni i manne simila t th COP command Thi comman function i th sam manne a th COP command excep tha th dat fro th sourc i compare o byte-by-byt basi wit th dat fro th destination Th paramete lis transferre t th targe i th sam a fo th COP command Thi paramete lis contain th informatio t identif th logica unit involve i th compariso an th lengt o th comparison (Se 7.1. fo additiona informatio abou th COP command. I th compariso i unsuccessful th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t MISCOMPARE Th remainin field i th extende sens shal b se a documente i th COP command. .pa 7.2.2 COPY AND VERIFY Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 3AH Table 7-22 COPY AND VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| Logica Uni Numbe Reserved BytCh |Reserved| -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| Paramete Lis Length (MSB | -----|-----------------------------------------------------------------------| 4 | Paramete Lis Length | -----|-----------------------------------------------------------------------| 5 | Paramete Lis Length (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Reserved | -----|-----------------------------------------------------------------------| 8 | Reserved | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th COP AN VERIF comman (Tabl 7-22 perform th sam functio a th COP command excep tha verificatio o th dat writte t th destinatio logica uni i performe afte th dat i written Th paramete lis transferre t th targe i th sam a fo th COP command Thi paramete lis contain th informatio t identif th logica unit involve i th cop an th lengt o th copy (Se 7.1. fo additiona informatio abou th COP command.) byt chec (BytChk bi o zer cause th verificatio t b simpl mediu verificatio (CRC ECC etc) BytCh bi o on cause byte-by- byt compariso o dat writte t th destinatio logica uni an th dat rea fro th sourc logica unit I th compariso i unsuccessful th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t MISCOMPARE Th remainin field i th extende sens shal b se a documente i th COP command. .pa 7. Grou Command fo Al Devic Types. Th Grou command (operatio code 40H throug 5FH ar al reserve fo futur standardization. 7. Grou Command fo Al Devic Types. Th Grou command (operatio code 60H throug 7FH ar al reserve fo futur standardization. 7. Grou Command fo Al Devic Types. Th Grou command (operatio code 80H throug 9FH ar al reserve fo futur standardization. 7. Grou Command fo Al Devic Types. Th Grou command wit operatio code A0H throug AFH ar vendo unique Th Grou command wit operatio code B0H throug BFH ar reserve fo futur standardization. 7. Grou Command fo Al Devic Types. Th Grou command (operatio code C0H throug DFH ar al vendo unique. 7. Grou Command fo Al Devic Types. Th Grou command (operatio code E0H throug FFH ar al vendo unique. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 8 # 8. Command Descriptions for Direct-Access Devices 8. Grou Command fo Direct-Acces Devices. Th Grou command fo direct-acces device shal b a show i Tabl 8-1. Table 8-1 Group 0 Commands for Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H O REZERO UNIT 8.1.1 02H V 03H M REQUEST SENSE 7.1.2 04H M FORMAT UNIT 8.1.2 05H V 06H V 07H O REASSIGN BLOCKS 8.1.3 08H M READ 8.1.4 09H V 0AH M WRITE 8.1.5 0BH O SEEK 8.1.6 0CH V 0DH V 0EH V 0FH V 10H V 11H V 12H E INQUIRY 7.1.3 13H V 14H V 15H O MODE SELECT 8.1.7 16H O RESERVE 8.1.8 17H O RELEASE 8.1.9 18H O COPY 7.1.4 19H V 1AH O MODE SENSE 8.1.10 1BH O START/STOP UNIT 8.1.11 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH O PREVENT/ALLOW MEDIUM REMOVAL 8.1.12 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 8.1.1 REZERO UNIT Command Peripheral Device Type: Direct Access Operation Code Type: Optional Operation Code: 01H Table 8-2 REZERO UNIT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REZER UNI comman (Tabl 8-2 request tha th targe se th logica uni t specifi state Se vendo specification fo details. 8.1.2 FORMAT UNIT Command Peripheral Device Type: Direct Access Operation Code Type: Mandatory Operation Code: 04H Table 8-3 FORMAT UNIT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | FmtData| CmpLst | Defect List Format | -----|-----------------------------------------------------------------------| 2 | Vendor Unique | -----|-----------------------------------------------------------------------| 3 | Interleave (MSB) | -----|-----------------------------------------------------------------------| 4 | Interleave (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== .pa Th FORMA UNI comman (Tabl 8-3 ensure tha th mediu i formatte s tha al dat block ca b accessed Ther i n guarante tha th mediu ha o ha no bee altered I addition th mediu ma b certifie an contro structure b create fo th managemen o th mediu an defects. Th FORMA UNI comman i bot mandator comman an a extende comman wit multipl options (see Table 8-4) Th FORMA UNI comman shal b rejecte wit RESERVATIO CONFLIC statu if any extent (see 8.1.8.2) in the specified logical unit is reserved. forma dat (FmtData bi o on indicate tha forma dat i supplie durin th DAT OU phase Th defec lis include wit thi dat specifie th defect tha shal b entere int th defec map Th forma o th defec lis i determine b defec lis format FmtDat bi o zer indicate tha th DAT OU phas shal no occur (n defec dat shal b supplie b th initiator) complet lis (CmpLst bi o on indicate th dat supplie i th complet lis o know defects An previou initiator-specifie defec ma o defec dat shal b erased Th targe ma ad t thi lis a i format th medium Th resul i t purg an previou initiator-specifie defec lis an t buil ne defec list CmpLs bi o zer indicate tha th dat supplie i i additio t existin defec dat usin th curren format Whe usin th bloc format th defec lis refer t th curren bloc lengt (an no t th ne bloc length i i i different an th defec lis refer t curren logica bloc addresse (no physica addresses) Th targe ma ad t thi lis a i format th medium. Th defec lis forma fiel specifie additiona informatio relate t th defec list (Se Tabl 8- fo furthe information.) Th interleav fiel request tha th logica block b relate i specifi fashio t th physica block t facilitat spee matching A interleav valu o zer request tha th targe us it defaul interleave A interleav valu o on request tha consecutiv logica block b place i consecutiv physica order Value o tw o greate ar vendo unique. .pa Table 8-4 FORMAT UNIT Command Variations ============================================================================== Bit Reference --------------------- 4 3 2 1 0 FmtData | CmpLst | | Defect List | | Format | | | | | Command Type Comments --------------------- ------------ -------------------------------------- 0 X X X X Mandatory Forma wit n defec dat sen fro th initiato t th target. 1 0 0 X X Extended Forma addin th defect specifie i th defec lis t th know defects (Se Tabl 8-5.) 1 1 0 X X Optional Forma usin defect i th defec lis a th ful se o know defects (Se Tabl 8-5.) 1 0 1 0 0 Optional Forma addin th defect i th defec lis t th know defects (Se Tabl 8-6.) 1 1 1 0 0 Optional Forma usin th defect i th defec lis a th ful se o know defects (Se Tabl 8-6.) 1 0 1 0 1 Optional Forma addin th defect i th defec lis t th know defects (Se Tabl 8-7.) 1 1 1 0 1 Optional Forma usin th defect i th defec lis a th ful se o know defects (Se Tabl 8-7.) 1 X 1 1 0 Vendor unique 1 0 1 1 1 Reserved 1 1 1 1 1 Reserved ============================================================================== X = 1 or 0 (i.e., don't care term). .pa Th defec list show i Table 8-5 8-6 an 8- contai four-byt heade followe b on o mor defec descriptors Th lengt o th defec descriptor var wit th forma o th defec list. Th defec lis lengt i eac tabl specifie th tota lengt i byte o th defec descriptor tha follow I Tabl 8-5 th defec lis lengt i equa t fou time th numbe o defec descriptors I Table 8- an 8-7 th defec lis lengt i equa t eigh time th numbe o defec descriptors. Table 8-5 Defect List - Block Format ============================================================================== Byte | Defect List Header | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 | Defect List Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Defect List Length (LSB) | ============================================================================== | Defec Descripto(s) | ============================================================================== 0 | Defect Block Address (MSB) | -----|-----------------------------------------------------------------------| 1 | Defect Block Address | -----|-----------------------------------------------------------------------| 2 | Defect Block Address | -----|-----------------------------------------------------------------------| 3 | Defect Block Address (LSB) | ============================================================================== Eac defec descripto fo th bloc forma specifie four-byt defec bloc addres tha contain th defect Th defec descriptor shal b i ascendin order. .pa Table 8-6 Defect List - Bytes From Index Format ============================================================================== Byte | Defect List Header | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 | Defect List Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Defect List Length (LSB) | ============================================================================== | Defec Descripto(s) | ============================================================================== 0 | Cylinder Number of Defect (MSB) | -----|-----------------------------------------------------------------------| 1 | Cylinder Number of Defect | -----|-----------------------------------------------------------------------| 2 | Cylinder Number of Defect (LSB) | -----|-----------------------------------------------------------------------| 3 | Head Number of Defect | -----|-----------------------------------------------------------------------| 4 | Defect Bytes from Index (MSB) | -----|-----------------------------------------------------------------------| 5 | Defect Bytes from Index | -----|-----------------------------------------------------------------------| 6 | Defect Bytes from Index | -----|-----------------------------------------------------------------------| 7 | Defect Bytes from Index (LSB) | ============================================================================== Eac defec descripto fo th byte fro inde forma specifie th beginnin o a eight-byt defec locatio o th medium Eac defec descripto i comprise o th cylinde numbe o defect th hea numbe o defect an th defec byte fro index Th defec descriptor shal b i ascendin order Fo determinin ascendin order th cylinde numbe o defec i considere th mos significan par o th addres an th defec byte fro inde i considere th leas significan par o th address. defec byte fro inde o FFFFFFFFH indicate tha th entir trac shal b reassigned. .pa Table 8-7 Defect List - Physical Sector Format ============================================================================== Byte | Defect List Header | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 | Defect List Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Defect List Length (LSB) | ============================================================================== | Defec Descripto(s) | ============================================================================== 0 | Cylinder Number of Defect (MSB) | -----|-----------------------------------------------------------------------| 1 | Cylinder Number of Defect | -----|-----------------------------------------------------------------------| 2 | Cylinder Number of Defect (LSB) | -----|-----------------------------------------------------------------------| 3 | Head Number of Defect | -----|-----------------------------------------------------------------------| 4 | Defect Sector Number (MSB) | -----|-----------------------------------------------------------------------| 5 | Defect Sector Number | -----|-----------------------------------------------------------------------| 6 | Defect Sector Number | -----|-----------------------------------------------------------------------| 7 | Defect Sector Number (LSB) | ============================================================================== Eac defec descripto fo th physica secto forma specifie sector- siz defec locatio comprise o th cylinde numbe o defect th hea numbe o defect an th defec secto number Th defec descriptor shal b i ascendin order Fo determinin ascendin order th cylinde numbe o defec i considere th mos significan par o th addres an th defec secto numbe i considere th leas significan par o th address. defec secto numbe o FFFFFFFFH indicate tha th entir trac shal b reassigned. .pa 8.1.3 REASSIGN BLOCKS Command Peripheral Device Type: Direct Access and Write-Once Read-Multiple Operation Code Type: Optional Operation Code: 07H Table 8-8 REASSIGN BLOCKS Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REASSIG BLOCK comman (Tabl 8-8 request th targe t reassig th defectiv logica block t a are o th logica uni reserve fo thi purpose. Th initiato transfer defec lis tha contain th logica bloc addresse t b reassigned Th targe shal reassig th physica mediu use fo eac logica bloc addres i th list Th dat containe i th logica block specifie i th defec lis ma b altered bu th dat i al othe logica block o th mediu shal b preserved. Th effec o specifyin logica bloc t b reassigne tha previousl ha bee reassigne i t reassig th bloc again Thus ove th lif o th medium logica bloc ca b assig t multipl physica addresse (until no more spare locations remain on the medium). Th REASSIG BLOCK defec lis (Tabl 8-9 contain four-byt heade followe b on o mor defec descriptors Th lengt o eac defec descripto i fou bytes. Th defec lis lengt specifie th tota lengt i byte o th defec descriptor tha follow Th defec lis lengt i equa t fou time th numbe o defec descriptors. .pa Table 8-9 REASSIGN BLOCKS Defect List ============================================================================== Byte | Defect List Header | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 | Defect List Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Defect List Length (LSB) | ============================================================================== | Defect Descriptor(s) | ============================================================================== 0 | Defect Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 1 | Defect Logical Block Address | -----|-----------------------------------------------------------------------| 2 | Defect Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Defect Logical Block Address (LSB) | ============================================================================== Th defec descripto specifie four-byt defec logica bloc addres tha contain th defect Th defec descriptor shal b i ascendin order. I th logica uni ha insufficien capacit t reassig al o th defectiv logica blocks th comman shal terminat wit CHEC CONDITIO statu an th sens ke shal b se t MEDIU ERROR Th logica bloc addres o th first logica bloc not reassigne shal b returne i th informatio byte o th sens data. .pa 8.1.4 READ Command Peripheral Device Type: Direct Access Operation Code Type: Mandatory Operation Code: 08H Table 8-10 READ Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA comman (Tabl 8-10 request tha th targe transfe dat t th initiator. Th logica bloc addres specifie th logica bloc at whic th rea operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat t transferred transfe lengt o zer indicate tha 25 logica block shal b transferred An othe valu indicate th numbe o logica block tha shal b transferred. Th mos recen dat valu writte i th addresse logica bloc shal b returned. Thi comman shal b terminate wit RESERVATIO CONFLIC statu i an reservatio acces conflic (se 8.1.8 exist an n dat shal b read. I an o th followin condition occur thi comman shal b terminate wit CHEC CONDITIO status an i extende sens i implemented th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus th CHEC CONDITIO status. .pa Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note) Target reset or medium change since last command from this initiator UNIT ATTENTION Unrecoverable read error MEDIUM ERROR Recovered read error RECOVERED ERROR Overrun or other error that might be resolved by repeating the command ABORTED COMMAND NOTE Th extende sens informatio byte shal b se t th logica bloc addres o th firs invali address. 8.1.5 WRITE Command Peripheral Device Type: Direct Access Operation Code Type: Mandatory Operation Code: 0AH Table 8-11 WRITE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT comman (Tabl 8-11 request tha th targe writ th dat transferre b th initiato t th medium. Th logica bloc addres specifie th logica bloc at whic th writ operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat t transferred transfe lengt o zer indicate tha 25 logica block shal b transferred An othe valu indicate th numbe o logica block tha shal b transferred. .pa Thi comman shal b terminate wit RESERVATIO CONFLIC statu i an reservatio acces conflic (se 8.1.8 exist an n dat shal b written. I an o th followin condition occur thi comman shal b terminate wit CHEC CONDITIO status an i extende sens i implemented th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus th CHEC CONDITIO status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note) Target reset or medium change since last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND NOTE Th extende sens informatio byte shal b se t th logica bloc addres o th firs invali address I thi case n dat shal b written o th logica unit. 8.1.6 SEEK Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 0BH Table 8-12 SEEK Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SEE comman (Tabl 8-12 request tha th logica uni see t th specifie logica bloc address. .pa 8.1.7 MODE SELECT Command Peripheral Device Type: Direct Access Operation Code Type: Optional Operation Code: 15H Table 8-13 MODE SELECT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SELEC comman (Tabl 8-13 provide mean fo th initiato t specif medium logica unit o periphera devic parameters to the target. Th paramete lis lengt specifie th lengt i byte o th MOD SELEC paramete lis tha shal b transferre durin th DAT OU phase paramete lis lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error. Th MOD SELEC paramete lis (Tabl 8-14 contain four-byt header followe b zer o mor bloc descriptors followe b th vendo uniqu parameters i any. .pa Table 8-14 MODE SELECT Parameter List ============================================================================== Byte | MODE SELECT Header | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Medium Type | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Bloc Descripto(s) | ============================================================================== 0 | Density Code | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== .pa .fo Section 8 93.1 Code values for the mediu typ field are defined in Table 8-14.1. Table 8-14.1 Direct-access Medium Type Codes ============================================================================== Code Value Medium Type ---------- ---------------------------------------------------------------- 00H Default medium type (currently mounted medium type) 01H Flexible disk, single-sided; unspecified medium 02H Flexible disk, double-sided; unspecified medium Flexible Disks Diameter Bit Density Track Density Number Reference mm (inch) Bits/Radian /mm (/inch) Of Sides Standard ---------- ----------- ------------- -------- -------------- 05H 200 (8.0) 6 631 1.9 (48) 1 X3.73-1980 06H 200 (8.0) 6 631 1.9 (48) 2 X3B8-140 09H 200 (8.0) 13 262 1.9 (48) 1 X3B8/78-139 0AH 200 (8.0) 13 262 1.9 (48) 2 X3.121-1984 0DH 130 (5.25) 3 979 1.9 (48) 1 X3.82-1980 12H 130 (5.25) 7 958 1.9 (48) 2 X3.125-1984 16H 130 (5.25) 7 958 3.8 (96) 2 X3.126-198X 1AH 130 (5.25) 13 262 3.8 (96) 2 DIS 8630 1EH 90 (3.5) 7 958 5.3 (135) 2 X3.137-198X Direct-access Magnetic Tapes Width Density Reference mm. (Inch) Tracks FTPMM (FTPI) Standard Note ----------- ------ ------------ ----------- ---- 40H 6.3 (0.25) 12 394 (10 000) X3B5/85-138 1 44H 6.3 (0.25) 24 394 (10 000) X3B5/85-138 1 80H _ FFH Vendor unique All others Reserved ============================================================================== NOTES: (1 Th reference standar i fo unrecorde miniatur cartridg media Th usag referre t her i fo seria GC recordin usin forma know a QIC-100 Sinc X3B issue ne documen numbe fo eac revisio o thei workin draf document pleas contac th Chairma o X3B fo th lates documen number. (2) See appendix F for additional standards that may be applicable. Th bloc descripto lengt specifie th lengt i byte o al th bloc descriptors I i equa t th numbe o bloc descriptor time eight and doe no includ th vendo uniqu parameters i any bloc descripto lengt o zer indicate tha n bloc descriptor shal b include i th paramete list Thi conditio shal no b considere a a error. Eac bloc descripto specifie th mediu characteristic fo al o par o logica unit Eac bloc descripto contain densit code numbe o blocks an bloc length. .pa .fo Section 8 93.2 Code values for the density code field shall be assigned as follows: 00H Default (default density of medium) 01H Flexible disk, single-density 02H Flexible disk, double-density 03H _ 7FH Reserved 80H _ FFH Vendor unique Th numbe o block fiel specifie th numbe o logica block o th mediu tha mee th densit cod an bloc lengt i th bloc descriptor numbe o block o zer indicate tha al o th remainin logica block o th logica uni shal hav th mediu characteristic specifie b th bloc descriptor. Th bloc lengt specifie th lengt i byte o eac logica bloc describe b th bloc descriptor. .pa .pn 94 .fo Section 8 # 8.1.8 RESERVE Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 16H Table 8-15 RESERVE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | 3rdPty | Third Party Device ID | Extent | -----|-----------------------------------------------------------------------| 2 | Reservation Identification | -----|-----------------------------------------------------------------------| 3 | Extent List Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Extent List Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RESERV comman (Tabl 8-15 i use t reserv logica unit or i th exten reservatio optio i implemented extent withi logica unit fo th us o th initiator I third-part reservatio optio i implemented th logica unit o extent ma b reserve fo anothe specifie SCS device Th RESERV an RELEAS command provid th basi mechanis fo contentio resolution in multiple-initiator systems. 8.1.8. Logica Uni Reservation. I th exten bi i zero thi comman shal reques tha th entir logica uni b reserve fo th exclusiv us o th initiato unti th reservatio i supercede b anothe vali RESERV comman fro th initiato tha mad th reservatio o unti release b RELEAS comman fro th sam initiator b BU DEVIC RESE messag fro an initiator o b "hard RESE condition logica uni reservatio shal no b grante i th logica uni o an exten i reserve b anothe initiator I shal b permissibl fo a initiato t reserv logica uni tha i currentl reserve b tha initiator I th exten bi i zero th reservatio identificatio an th exten lis lengt shal b ignored. I th logica unit o an exten withi th logica uni i reserve fo anothe initiator the targe shal respon b either: (1) returning RESERVATIO CONFLIC statu (2 queuin th reservatio reques an the disconnectin unti al previousl queue reservation hav bee release an th logica uni i available the reconnectin t perfor th reservation If afte honorin th reservation an othe initiato the subsequentl attempt t perfor an comman o th reserve logica uni othe tha RESERV command whic ma b queued o RELEAS command whic shal b ignored the th comman shal b rejecte wit RESERVATIO CONFLIC status 8.1.8. Exten Reservatio (Optional). Th reservatio identificatio provide mean fo a initiato t identif eac exten reservation Thi allow a initiato i multipl taskin environment t hav multipl reservation outstanding Th reservatio identificatio i use i th RELEAS comman t specif whic reservatio i t b released I i als use i supercedin RESERV command t specif whic reservatio i t b superceded. I th exten reservatio optio i implemented the th exten releas optio (se 8.1.9.2 shal als b implemented Thes option permi multipl extent withi th logica uni t b reserved eac wit separat reservatio type I th exten bi i one an th exten reservatio optio i implemented then the target shall process the reservation request as follows (1 Th exten lis shal b checke fo the numbe o extent i th reservatio request I th exten lis lengt i zero n reservation shal b change an thi conditio shal no b treate a a error I th exten lis contain mor extent tha ar supporte o th logica unit th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t ILLEGA REQUEST I th exten lis contain mor extent tha ar currentl availabl o th logica unit the th targe shal either: (a retur RESERVATIO CONFLIC statu (b queu th reques an disconnec unti sufficien extent ar mad available Whe sufficien extent ar available th targe shal reconnec t continu processin th request. (2 Th exten lis shal b checke fo vali exten logica bloc addresses I an logica bloc addres i invali fo thi logica unit th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t ILLEGA REQUEST Th exten lis shal b checke fo invali exten overlap (a define b reservatio type wit othe exten descriptor i th exten lis an i invali overlap ar found th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t ILLEGA REQUEST. (3 I th requeste reservatio doe no conflic wit an activ o previousl requeste reservation th extent specifie shal b reserve unti supercede b anothe vali RESERV comman fro th initiato tha mad th reservatio o unti release b RELEAS comman fro th sam initiator b BU DEVIC RESE messag fro an initiator o b "hard RESE condition I eithe o th las tw condition occur th nex comman fro eac initiato shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t UNI ATTENTION. (4 I th reservatio reques conflict wit reservatio alread activ o reservatio reques tha i alread queued the th targe shal either: (a) return RESERVATION CONFLICT status (b queu th reservatio an disconnec unti i i allowe t b active Reservation ar onl mad activ whe al extent ar fre fro conflic wit activ o previousl queue reservations. I th exten bi i one an th exten reservatio optio i no implemented the th RESERV comman shal b rejecte wit CHEC CONDITIO statu an the sens ke shall be set to ILLEGA REQUEST. Table 8-16 Data Format of Extent Descriptors ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Reserved | RelAdr | Reservation Type| -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 5 | Logical Block Address | -----|-----------------------------------------------------------------------| 6 | Logical Block Address | -----|-----------------------------------------------------------------------| 7 | Logical Block Address (LSB) | ============================================================================== Th siz o th exten lis shal b define b th exten lis lengt parameter Th exten lis shal consis o zer o mor descriptor a show i Tabl 8-16 Eac exten descripto define a exten beginnin a th specifie logica bloc addres fo th specifie numbe o blocks I th numbe o block i zero th exten shal begi a th specifie logica bloc addres an continu throug th las logica bloc addres o th logica unit. Th reservatio typ fiel shal determin th typ o reservatio t b effecte fo eac extent Fou type o reservation ar possibl a follows: DB(1) DB(0) Reservation Type ----- ----- ---------------- 1 Rea Exclusive 0 1 Write Exclusive 1 1 Exclusive Access 0 0 Read Shared Rea Exclusive. Whil thi reservatio i active n othe initiato shal b permitte rea operation t th indicate extent Thi reservatio shal no inhibi writ operation fro an initiato o conflic wit writ exclusiv reservation however rea exclusive exclusiv access an rea share reservation that overla thi exten shal conflic wit thi reservation. Writ Exclusive. Whil thi reservatio i active n othe initiato shal b permitte writ operation t th indicate extent Thi reservatio shal no inhibi rea operation fro an initiato o conflic wit rea exclusiv reservatio fro an initiator Thi reservatio shal conflic wit writ exclusive exclusiv access an rea share reservation that overla thi extent. Exclusiv Access. Whil thi reservatio i active n othe initiato shal b permitte an acces t th indicate extent Al reservatio type that overla thi exten shal conflic wit thi reservation. Rea Shared. Whil thi reservatio i active n writ operation shal b permitte b an initiato t th indicate extent Thi reservatio shal no inhibi rea operation fro an initiato o conflic wit rea share reservation Rea exclusive writ exclusive an exclusiv acces reservation tha overla wit thi exten shal conflic wit thi reservation. I th relativ addres bi i one th logica bloc addres shal b treate a two' complemen displacement Thi displacemen shal b adde t th logica bloc addres las accesse o th logica uni t for th logica bloc addres fo thi extent Thi featur i onl availabl whe linkin command an require tha previou comman i th linke grou ha accesse logica bloc o th logica unit i not th RESERV comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t ILLEGA REQUEST. I a initiato attempt comman t logica bloc that ha bee reserve an tha acces i prohibite b th reservation th comman shal no b performe an th comman shal b terminate wit RESERVATIO CONFLIC status I reservatio conflic preclude an par o th command non o th comman shal b performed COP command shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t DAT PROTEC i an par o th cop operatio i prohibite b a activ reservation I an exten i logica uni i reserve i an way FORMA UNI comman shal b rejecte wit RESERVATIO CONFLIC status. 8.1.8. Thir Part Reservatio (Optional). Th third-part reservatio optio fo th RESERV comman allow a initiato t reserv logica uni o extent withi logica uni fo anothe SCS device Thi optio i intende fo us i multiple-initiato system tha us th COP command An targe tha implement th third-part reservatio optio shal als implemen th third-part releas optio (se 8.1.9.3). I th third-part (3rdPty bi i zero the th third-part reservatio optio i no requested I th 3rdPt bi i on an th third-part reservatio optio i implemented the th RESERV comman shal reserv th specifie logica uni o extent fo th SCS devic specifie i th third- part devic I field Th targe shal preserv th reservatio unti i i supercede b anothe vali RESERV comman fro th initiato tha mad th reservatio o unti i i release b th sam initiator b BU DEVIC RESE messag fro an initiator o "hard RESE condition Th targe shal ignor an attemp t releas th reservatio mad b an othe initiator. I th 3rdPt bi i on an th third-part reservatio optio i no implemented the th targe shal rejec th RESERV comman wit a CHEC CONDITIO statu an the sens ke shall be set to ILLEGA REQUEST 8.1.8. Supercedin Reservations. A initiato tha hold curren reservatio ma modif tha reservatio b issuin anothe RESERV comman t th sam logica uni and i th exten bi i one usin th sam reservatio identification Th supercedin RESERV comman shal releas th previou reservatio stat whe th ne reservatio reques i granted Th previou reservatio shal no b modifie i th ne reservatio reques canno b granted I th supercedin reservatio canno b grante becaus o conflict wit previou activ reservatio (othe tha th reservatio bein superceded) the th targe shal either: (1) return RESERVATION CONFLICT status (2 queu th reservatio reques an disconnec unti i i allowe t b active Th reservatio reques shal b mad activ whe i i fre fro conflict with all active reservations. supercedin reservatio take priority over any previously queued reservation request. IMPLEMENTOR NOTE Supercedin reservation ar principall intende t allo th SCS devic I t b change o reservatio usin th third-part reservatio option Thi capabilit i necessar fo certai situation whe usin th COP command. 8.1.9 RELEASE Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 17H Table 8-17 RELEASE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | 3rdPty | Third Party Device ID | Extent | -----|-----------------------------------------------------------------------| 2 | Reservation Identification | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RELEAS comman (Tabl 8-17 i use t releas previousl reserve logica units or i th exten releas optio i implemented previousl reserve extent withi logica units I i no a erro fo a initiato t attemp t releas reservatio tha i no currentl active I thi case the target returns GOOD status without altering any other reservation. 8.1.9. Logica Uni Release. I th exten bi i zero thi comman shal caus th targe t terminat al logica uni an exten reservation tha ar activ fro th initiato t th specifie logica unit. 8.1.9. Exten Releas (Optional). I th exten bi i on an th exten releas optio i no implemented the th RELEAS comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t ILLEGA REQUEST Thi optio shal b implemente i th exten reservatio optio (se 8.1.8.2 i implemented. I th exten bi i on an th exten releas optio i implemented thi comman shal caus an reservatio fro th requestin initiato wit matchin reservatio identificatio t b terminated Othe reservation fro th requestin initiato shal remai i effect. I th logica uni queue reservations the whe RELEAS comman i processed th reservatio queu shal b examine o first-i first-ou basis I ther ar on o mor reservation i th queu tha ca no b activated th logica uni shal firs disconnec fro th initiator I shal the successivel reconnec wit eac initiato whos queue reservatio ma no b activated queue reservatio reques shal no b activate i i conflict wit an previousl queue reservation Afte firs grantin al possibl queue reservations th uni shal reconnec wit th initiato o th RELEAS command to terminate the command. I logica uni tha queue reservation receive RELEAS comman fro secon initiato whil i i disconnecte durin processin o previou RELEAS command i shal the disconnec fro th secon initiato an suspen processin o th secon RELEAS unti afte reconnectio wit th firs initiator o unti i i determine tha reconnectio ha failed. 8.1.9. Thir Part Releas (Optional). Th third-part releas optio fo th RELEAS comman allow a initiato t releas logica uni o extent withi logica uni tha wer previousl reserve usin th third- part reservatio optio (se 8.1.8.3) Thi optio shal b implemente i th third-part reservatio optio i implemented Thi optio i intende fo us i multiple-initiato system tha us th COP command. I th third-part (3rdPty bi i zero the th third-part releas optio i no requested I th 3rdPt bi i on an th targe implement th third-part releas option the th targe shal releas th specifie logica uni o extents bu onl i th reservatio wa mad usin th third- part reservatio optio b th initiato tha i requestin th releas fo th sam SCS devic a specifie i th third-part devic I field. I th 3rdPt bi i on an th targe doe no implemen th third-part releas option the th targe shal terminat th comman wit CHEC CONDITIO statu an th sens ke shall be se t ILLEGA REQUEST. .pa 8.1.10 MODE SENSE Command Peripheral Device Type: Direct Access Operation Code Type: Optional Operation Code: 1AH Table 8-18 MODE SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SENS comman (Tabl 8-18 provide mean fo targe t repor it medium logica unit o periphera devic parameter t th initiator I i complementar comman t th MOD SELEC comman fo suppor o mediu tha ma contai multipl bloc length o densities. Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo returne MOD SENS data A allocatio lengt o zer indicate tha n MOD SENS dat shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl MOD SENS dat have bee transferre t th initiator, whichever is less Th MOD SENS dat (Tabl 8-19 contain four-byt header followe b zer o mor eight-byt bloc descriptors followe b th vendo uniqu parameters i any .pa Table 8-19 MOD SENS Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Sense Data Length | -----|-----------------------------------------------------------------------| 1 | Medium Type | -----|-----------------------------------------------------------------------| 2 | WP | Reserved | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Bloc Descripto(s) | ============================================================================== 0 | Density Code | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== Th sens dat lengt specifie th lengt i byte o th followin MOD SENS dat tha i availabl t b transferre durin th DAT I phase Th sense data length does not include itself. Code values for the medium type field are defined in Table 8-14.1. writ protecte (WP bi o zer indicate tha th mediu i writ enabled W bi o on indicate tha th mediu i writ protected. Th bloc descripto lengt specifie th lengt i byte o al th bloc descriptors I i equa t th numbe o bloc descriptor time eight and doe no includ th vendo uniqu parameters i any bloc descripto lengt o zer indicate tha n bloc descriptor shal b include i th paramete list Thi conditio shal no b considere a a error. Eac bloc descripto specifie th mediu characteristic fo al o par o logica unit Eac bloc descripto contain densit code numbe o blocks an bloc length. Code values for the density code field shall be assigned as follows: 00H Default (only one density supported) 01H Flexible disk, single density 02H Flexible disk, double density 03H _ 7FH Reserved 80H _ FFH Vendor unique Th numbe o block fiel specifie th numbe o logica block o th mediu tha meet th densit cod an bloc lengt i th bloc descriptor numbe o block o zer indicate tha al o th remainin logica block o th logica uni hav th mediu characteristic specifie b th bloc descriptor. The block length specifies the length in bytes of each logical block. 8.1.11 START/STOP UNIT Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 1BH Table 8-20 START/STOP UNIT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Immed | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | Start | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th START/STO UNI comman (Tabl 8-20 request tha th targe enabl o disabl the logica uni fo furthe operations. A immediat (Immed bi o on indicate tha statu shal b returne a soo a th operatio i initiated A Imme bi o zer indicate tha statu shal b returne afte th operatio i completed. star bi o on request th logica uni b mad read fo use star bi o zer request tha th logica uni b stopped .pa 8.1.12 PREVENT/ALLOW MEDIUM REMOVAL Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 1EH Table 8-21 PREVENT/ALLOW MEDIUM REMOVAL Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | Prevent| -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th PREVENT/ALLO MEDIU REMOVA comman (Tabl 8-21 request tha th targe enabl o disabl th remova o th mediu i th logica unit. preven bi o on shal inhibi mechanism tha normall allo remova o th medium preven bi o zer shal allo remova o th medium. Thi preventio o mediu remova conditio shal terminat upo receip o PREVENT/ALLO MEDIU REMOVA comman wit th preven bi se t zero o b th receip o BU DEVIC RESE messag fro an initiato o b "hard RESE condition. .pa 8. Grou Command fo Direct-Acces Devices. Th Grou command fo direct-acces device shal b a show i Tabl 8-22. Table 8-22 Group 1 Commands for Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 20H V 21H V 22H V 23H V 24H V 25H E READ CAPACITY 8.2.1 26H V 27H V 28H E READ 8.2.2 29H V 2AH E WRITE 8.2.3 2BH O SEEK 8.2.4 2CH V 2DH V 2EH O WRITE AND VERIFY 8.2.5 2FH O VERIFY 8.2.6 30H O SEARCH DATA HIGH 8.2.7.1 31H O SEARCH DATA EQUAL 8.2.7.2 32H O SEARCH DATA LOW 8.2.7.3 33H O SET LIMITS 8.2.8 34H R 35H R 36H R 37H R 38H R 39H O COMPARE 7.2.1 3AH O COPY AND VERIFY 7.2.2 3BH R 3CH R 3DH R 3EH R 3FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 8.2.1 READ CAPACITY Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Extended Operation Code: 25H Table 8-23 READ CAPACITY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Reserved | -----|-----------------------------------------------------------------------| 8 | Vendor Unique | Reserved | PMI | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA CAPACIT comman (Tabl 8-23 provide mean fo th initiato t reques informatio regardin th capacit o th logica unit. partia mediu indicato (PMI bi o zer indicate tha th informatio returne i th REA CAPACIT dat shal b th logica bloc addres an bloc lengt (i bytes o th las logica bloc o th logica unit Th logica bloc addres i th comman descripto bloc shal b t se zer fo thi option. PM bi o on indicate tha th informatio returne shal b th logica bloc addres an bloc lengt (i bytes o th las logica bloc address after which substantia dela i dat transfe wil b encountere. Thi logica bloc addres shal b greate tha o equa t th logica bloc addres specifie i th comman descripto block (Implementor note Thi functio i intende t assis storag managemen softwar i determinin whethe ther i sufficien spac o th curren track cylinder etc t contai frequentl accesse dat structur suc a fil director o fil index.) Th eigh byte o REA CAPACIT dat show i Tabl 8-24 shal b sen durin th DAT I phas o th command. Table 8-24 REA CAPACIT Data ============================================================================== Byte | Description | ============================================================================== 0 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 1 | Logical Block Address | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 5 | Block Length | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== 8.2.2 READ Command Peripheral Device Type: Direct Access Operation Code Type: Extended Operation Code: 28H Table 8-25 READ Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA comman (Tabl 8-25 request tha th targe transfe dat t th initiator. Th logica bloc addres specifie th logica bloc at which th rea operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat tha shal b transferred transfe lengt o zer indicate tha n logica block shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th numbe o logica block tha shal b transferred. Th mos recen dat valu writte i th addresse logica bloc shal b returned. Thi comman shal b terminate wit RESERVATIO CONFLIC statu i an reservatio acces conflic (se 8.1.8 exist an n dat shal b read. I an o th followin condition occur thi comman shal retur CHEC CONDITIO statu an th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus th CHEC CONDITIO status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note) Target reset or medium change since last command from this initiator UNIT ATTENTION Unrecovered read error MEDIUM ERROR Recoverabl rea erro RECOVERE ERROR Overrun or other error that might be resolved by repeating the command ABORTED COMMAND NOTE Th extende sens informatio byte shal b se t th logica bloc addres o th firs invali address .pa 8.2.3 WRITE Command Peripheral Device Type: Direct Access Operation Code Type: Extended Operation Code: 2AH Table 8-26 WRITE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT comman (Tabl 8-26 request tha th targe writ th dat transferre b th initiato t th medium. Th logica bloc addres specifie th logica bloc at which th writ operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat tha shal b transferred transfe lengt o zer indicate tha n logica block shal b transferred Thi conditio shal no b considere a a erro an n dat shal b written An othe valu indicate the numbe o logica block that shal b transferred. Thi comman shal b terminate wit RESERVATIO CONFLIC statu i an reservatio acces conflic (se 8.1.8 exist an n dat shal b written. I an o th followin condition occur thi comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus th CHEC CONDITIO status. .pa Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note) Target reset or medium change since the last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND NOTE Th extende sens informatio byte shal b se t th logica bloc addres o th firs invali address I thi case n dat shal b written o th logica unit 8.2.4 SEEK Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 2BH Table 8-27 SEEK Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Reserved | -----|-----------------------------------------------------------------------| 8 | Reserved | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SEE comman (Tabl 8-27 request tha th logica uni see t th specifie logica bloc address. .pa 8.2.5 WRITE AND VERIFY Command Peripheral Device Type: Direct Access Operation Code Type: Optional Operation Code: 2EH Table 8-28 WRITE AND VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BytChk | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT AN VERIF comman (Tabl 8-28 request tha th targe writ th dat transferre fro th initiato t th mediu an the verif tha th dat i correctl written. byt chec (BytChk bi o zer cause th verificatio t b simpl mediu verificatio (CRC ECC etc) BytCh bi o on cause byte-by- byt compar o dat writte on th periphera devic an th dat transferre fro th initiator I th compar i unsuccessfu, th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t MISCOMPARE. Th logica bloc addres specifie th logica bloc a whic th writ operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat tha shal b transferred transfe lengt o zer indicate tha n logica block shal b transferred Thi conditio shal no b considere a a erro an n dat shal b written An othe valu indicate th numbe o logica block tha shal b transferred. .pa 8.2.6 VERIFY Command Peripheral Device Type: Direct Access Operation Code Type: Optional Operation Code: 2FH Table 8-29 VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BytChk | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Verification Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Verification Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th VERIF comman (Tabl 8-29 request tha th targe verif th dat writte o th medium. byt chec (BytChk bi o zer cause th verificatio t b simpl mediu verificatio (CRC ECC etc) BytCh bi o on cause byte-by- byt compar o dat o th mediu an th dat transferre fro th initiator I th compar i unsuccessful th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shall be se t MISCOMPARE. Th logica bloc addres specifie th logica bloc a whic th verif operatio shal begin. Th verificatio lengt specifie th numbe o contiguou logica block o dat tha shal b verified transfe lengt o zer indicate tha n logica block shal b verified Thi conditio shal no b considere a a error An othe valu indicate th numbe o logica block tha shal b verified. .pa 8.2.7 SEARCH DATA Commands Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 30H, 31H, or 32H Table 8-30 SEARCH DATA Commands ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Invert | Reserved | SpnDat | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SEARC DAT command (Tabl 8-30 searc on o mor logica block fo equalit o inequalit t dat pattern Th concep o record withi logica bloc i use t allo multipl record withi logica bloc t b searched. Th inver bi determine whethe th searc conditio i t b inverted Se 8.2.7. throug 8.2.7. fo descriptio o th searc condition fo th individua SEARC DAT commands. spanne dat (SpnDat bi o zer indicate tha eac recor shal b wholl containe withi singl block An spac a th en o bloc tha i smalle tha th recor lengt i ignore b th SEARC DAT commands SpnDa bi o on indicate tha record spa bloc boundaries Thus recor ma star i on bloc an en i th nex o subsequen block. transfe lengt o zer indicate tha n dat shal b searched Thi conditio shal b treate th sam a a unsatisfied search lin bi o zer indicate nonlinke comman an i th searc i satisfied th comman shal b terminate wit CONDITIO ME status REQUES SENS comman ca the b issue t determin th logica bloc addres an recor offse o th matchin record I th searc i no satisfie an n erro occurs th comman shal b terminate wit GOO status. A lin bit o one indicate comman i linke t th SEARC DAT comman an i th searc i satisfied CONDITIO ME statu i returne an th nex comman i executed I th RelAd bi i th nex comman i one th logica bloc addres o th nex comman i use a displacemen fro th logica bloc addres a whic th searc wa satisfied I linke searc i no satisfied th comman i terminate wit CHEC CONDITIO status REQUES SENS comman ma the b issued. REQUES SENS comman followin a satisfie SEARC DAT comman shall: (1 Retur sens ke o EQUA i th searc wa satisfie b a exac match I th searc wa satisfie b a inequalit the sens ke o N SENS shal b returned. (2) Return th vali bi set t one. (3 Retur th logica bloc addres o th logica bloc containin th firs matchin recor i th informatio bytes. (4 Retur th recor offse o th matchin recor i th firs fou byte o additiona sens bytes. REQUES SENS comman followin a unsatisfie SEARC DAT comman shall: (1 Retur sens ke o N SENSE i n error occurre durin th comman execution. (2) Return th vali bi set t zero. Th SEARC DAT paramete lis (Tabl 8-31 contain fourteen-byt header followe b on o mor searc argumen descriptors .pa Table 8-31 SEARCH DATA Parameter List ============================================================================== Byte | Parameter List Header | ============================================================================== 0 | Logical Record Length (MSB) | -----|-----------------------------------------------------------------------| 1 | Logical Record Length | -----|-----------------------------------------------------------------------| 2 | Logical Record Length | -----|-----------------------------------------------------------------------| 3 | Logical Record Length (LSB) | -----|-----------------------------------------------------------------------| 4 | First Record Offset (MSB) | -----|-----------------------------------------------------------------------| 5 | First Record Offset | -----|-----------------------------------------------------------------------| 6 | First Record Offset | -----|-----------------------------------------------------------------------| 7 | First Record Offset (LSB) | -----|-----------------------------------------------------------------------| 8 | Number of Records (MSB) | -----|-----------------------------------------------------------------------| 9 | Number of Records | -----|-----------------------------------------------------------------------| 10 | Number of Records | -----|-----------------------------------------------------------------------| 11 | Number of Records (LSB) | -----|-----------------------------------------------------------------------| 12 | Search Argument Length (MSB) | -----|-----------------------------------------------------------------------| 13 | Search Argument Length (LSB) | ============================================================================== | Search Argument Descriptor(s) | ============================================================================== 0 | Displacement (MSB) | -----|-----------------------------------------------------------------------| 1 | Displacement | -----|-----------------------------------------------------------------------| 2 | Displacement | -----|-----------------------------------------------------------------------| 3 | Displacement (LSB) | -----|-----------------------------------------------------------------------| 4 | Pattern Length (MSB) | -----|-----------------------------------------------------------------------| 5 | Pattern Length (LSB) | -----|-----------------------------------------------------------------------| 6 _ n| Pattern | ============================================================================== Th logica recor lengt fiel specifie th recor lengt i byte. Th firs recor offse fiel specifie th numbe o byte tha shal b ignore i th firs logica bloc befor th searc begins Th valu i th firs recor offse fiel shal no excee th lengt o th logica block Subsequen logica block shal b searche beginnin wit th firs byt i th logica block Thi permit on o mor record t b skippe initially. Th numbe o record fiel specifie th maximu numbe o record tha shal b searche b thi command A unsatisfie searc shal terminat whe th numbe o record o th numbe o block (fro th comman descripto block hav bee exhausted. Th searc argumen lengt specifie th lengt i byte o al th searc argumen descriptor tha follow Sinc th patter lengt ca vary ther i n fixe multipl o th searc argumen descripto t determin th searc argumen length. Th searc argumen descriptor specif on o mor searc condition t execute withi singl recor i orde t satisf th search Eac searc argumen descripto i mad u o displacement patter length an pattern Th displacemen fiel specifie th displacemen i byte o th firs byt o th dat t b compare fro th star o th logica record. Th patter lengt fiel specifie th lengt i byte o th patter tha follows. Th patter specifie th dat t compar t th logica record. 8.2.7. SEARC DAT HIG Command. Th SEARC DAT HIG comman (Tabl 8-30 operatio cod 30H shal b satisfie b th firs logica recor searche tha contain dat tha satisfie al o th searc argumen descriptor(s) I th inver bi i th comman descripto bloc i zero th searc argumen descriptor(s shal b satisfie b dat i th logica recor bein greate tha th dat i th pattern I th inver bi i one th searc argumen descriptor(s shal b satisfie b dat i th logica recor bein les tha o equa t th dat i th pattern (Se 8.2.7.) 8.2.7. SEARC DAT EQUA Command. Th SEARC DAT EQUA comman (Table8-30 operatio cod 31H shal b satisfie b th firs logica recor searche tha contain dat tha satisfie al o th searc argumen descriptor(s) I th inver bi i th comman descripto bloc i zero th searc argumen descriptor(s shal b satisfie b dat i th logica recor bein equa t th dat i th pattern I th inver bi i one th searc argumen descriptor(s shal b satisfie b dat i th logica recor bein no equa t th dat i th pattern (Se 8.2.7.) 8.2.7. SEARC DAT LO Command. Th SEARC DAT LO comman (Tabl 8-30 operatio cod 32H shal b satisfie b th firs logica recor searche tha contain dat tha satisfie al o th searc argumen descriptor(s) I th inver bi i th comman descripto bloc i zero th searc argumen descriptor(s shal b satisfie b dat i th logica recor bein les tha th dat i th pattern I th inver bi i one th searc argumen descriptor(s shal b satisfie b dat i th logica recor bein greate tha o equa t th dat i th pattern (Se 8.2.7.) .pa 8.2.8 SET LIMITS Command Peripheral Device Type: Direct Access, Write-Once Read-Multiple, and Read-Only Direct Access Operation Code Type: Optional Operation Code: 33H Table 8-32 SET LIMITS Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RdInh | WrInh | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 8 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SE LIMIT comman (Tabl 8-32 define th rang withi whic subsequen linke command ma operate secon SE LIMIT comman ma no b linke t chai o command i whic SE LIMIT comman ha alread bee issued. rea inhibi (RdInh bi o on indicate tha rea operation withi th rang ar inhibited writ inhibi (WrInh bi o on indicate tha writ operation withi th rang ar inhibited. Th logica bloc addres specifie th startin addres fo th range Th numbe o block specifie th numbe o logica block withi th range numbe o block o zer indicate tha th rang shal exten t th las logica bloc o th logica unit. An attemp t acces outsid o th restricte rang o an attemp t perfor a inhibite operatio withi th restricte rang shal no b performe. Th comman shal b terminate wit CHEC CONDITIO statu and i extende sens i implemented th sens ke shal b se t DAT PROTECT secon SE LIMIT comman withi linke lis o command shal b rejecte wit CHEC CONDITIO statu and i extende sens i implemented th sens ke shal b se t DAT PROTECT. .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 9 # 9. Group 0 Command Descriptions for Sequential-Access Devices Th Grou command fo sequential-acces device shal b a show i Table9-1. Table 9-1 Group 0 Commands for Sequential-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H M REWIND 9.1 02H V 03H M REQUEST SENSE 7.1.2 04H R 05H E READ BLOCK LIMITS 9.2 06H V 07H V 08H M READ 9.3 09H V 0AH M WRITE 9.4 0BH O TRACK SELECT 9.5 0CH V 0DH V 0EH V 0FH O READ REVERSE 9.6 10H M WRITE FILEMARKS 9.7 11H O SPACE 9.8 12H E INQUIRY 7.1.3 13H O VERIFY 9.9 14H O RECOVER BUFFERED DATA 9.10 15H O MODE SELECT 9.11 16H O RESERVE UNIT 9.12.1 17H O RELEASE UNIT 9.12.2 18H O COPY 7.1.4 19H O ERASE 9.13 1AH O MODE SENSE 9.14 1BH O LOAD/UNLOAD 9.15 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH O PREVENT/ALLOW MEDIUM REMOVAL 9.16 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 9.1 REWIND Command Peripheral Device Type: Sequential Access Operation Code Type: Mandatory Operation Code: 01H Table 9-2 REWIND Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Immed | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REWIN comman (Tabl 9-2 request tha th targe rewin th logica uni t the beginning-of-mediu o load-point A immediat (Immed bi o on indicate tha statu shal b returne a soo a th operatio i initiated A Imme bi o zer indicate tha statu shal b returne afte th operatio i completed. .pa 9.2 READ BLOCK LIMITS Command Peripheral Device Type: Sequential Access Operation Code Type: Extended Operation Code: 05H Table 9-3 READ BLOCK LIMITS Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA BLOC LIMIT comman (Tabl 9-3 request tha th target' capabilit fo bloc lengt limit b returne fo th logica unit Th REA BLOC LIMIT dat show i Tabl 9- shal b sen durin th DAT I phas o th command. Table 9-4 REA BLOC LIMIT Data ============================================================================== Byte | Description | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Maximum Block Length (MSB) | -----|-----------------------------------------------------------------------| 2 | Maximum Block Length | -----|-----------------------------------------------------------------------| 3 | Maximum Block Length (LSB) | -----|-----------------------------------------------------------------------| 4 | Minimum Block Length (MSB) | -----|-----------------------------------------------------------------------| Minimu Bloc Lengt (LSB | ============================================================================== I th maximu bloc lengt equal th minimu bloc length onl fixed- lengt block o th lengt indicate ar supported Otherwise variable- lengt block ar supported Fo variable-lengt blocks i th maximu bloc lengt equal zero n uppe limi i specified. .pa 9.3 READ Command Peripheral Device Type: Sequential Access Operation Code Type: Mandatory Operation Code: 08H Table 9-5 READ Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Fixed | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA comman (Tabl 9-5 transfer on o mor block(s t th initiato beginnin wit th nex bloc o th logica unit Th fixe bi specifie bot th meanin o th transfe lengt fiel an whethe fixed-lengt o variable-lengt block(s ar t b transferred. I th fixe bi i zero singl bloc shal b transferre wit th transfe lengt specifyin th maximu numbe o byte th initiato ha allocate fo th returne data I th actua bloc lengt i differen fro th specifie transfe length a CHEC CONDITIO statu shal b sen t th initiato an th incorrec lengt indicato (ILI bi an vali bi i extende sens shal b se t one Th informatio byte i extende sens shal b se t th differenc (residue betwee th requeste transfe lengt an th actua bloc length Target tha d no suppor negativ residue shal se th IL bi t on an th residu t zer whe th actua bloc lengt i large tha th transfe length I an case n mor tha transfe lengt byte shal b transferre t th initiato an th mediu shal b positione afte th bloc (end-of-mediu side). I th fixe bi i one th transfe lengt specifie th numbe o block t b transferre t th initiator Thi for o th REA comman i vali onl i th logica uni i currentl operatin i fixe bloc mode logica uni i i fixe bloc mod whe eithe o th followin condition ar true: (1 Th logica uni report th sam valu fo minimu bloc lengt an maximu bloc lengt i respons t th REA BLOC LIMIT command I thi case th curren bloc lengt i th valu returned. (2 Th logica uni uni ha bee instructe t us fixed-lengt block wit th MOD SELEC command I thi case th curren bloc lengt i th bloc lengt define i th MOD SELEC command. Otherwise th logica uni i i variabl bloc mode Th targe ma implemen fixe bloc mode variabl bloc mode o bot modes I th fixe bi doe no matc th curren mode o th mod indicate b th fixe bi i no implemented th targe shal rejec th comman b returnin a CHEC CONDITIO statu an b settin th sens ke t ILLEGA REQUEST. successfu REA comman wit th fixe bi equa t on shal transfe th curren bloc lengt time th transfe lengt byte o dat t th initiator Upo terminatio o th REA command th mediu shal b positione afte th las bloc transferre (end-of-mediu side). I th fixe bi i on an i bloc i rea tha i large o smalle tha th curren bloc length CHEC CONDITIO statu shal b returne t th initiator Th IL bi an th vali bi i extende sens shal b se t one Th informatio byte shal b se t th differenc (residue betwee th requeste transfe lengt an th actua numbe o block rea (no includin th incorrec lengt block) Upo termination th mediu shal b positione afte th incorrec lengt bloc (end-of-mediu side) I logica uni read filemar durin REA command i shal sen CHEC CONDITIO statu t th initiato an shal se th filemar bi i extende sense Upo termination th mediu shal b positione afte th filemar (end-of-mediu side) I th fixe bi i one th targe shal se th vali bi t on an th informatio byte shal b se t th differenc (residue betwee th requeste transfe lengt an th actua numbe o block rea (no includin th filemark). I logica uni encounter th physica end-of-mediu durin REA command th targe shal retur CHEC CONDITIO statu t th initiato an shal se th end-of-mediu (EOM bi t on i extende sense Th sens ke shal b se t MEDIU ERROR I th fixe bi i one th targe shal se th vali bi t on an th informatio byte t th differenc (residue betwee th requeste transfe lengt an th actua numbe o block successfull read Th mediu positio followin thi conditio i no defined Whe th transfe lengt i zero n dat shal b transferre an th curren positio o th logica uni shal no b changed Thi conditio shal no b considere a a error .pa 9.4 WRITE Command Peripheral Device Type: Sequential Access Operation Code Type: Mandatory Operation Code: 0AH Table 9-6 WRITE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Fixed | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT comman (Tabl 9-6 transfer on o mor block(s fro th initiato t th curren positio o th logica unit Th fixe bi specifie bot th meanin o th transfe lengt fiel an whethe fixed- lengt o variable-lengt block(s ar t b transferred. I th fixe bi i zero singl bloc shal b transferre fro th initiato an shal b writte t th logica uni beginnin a th curren mediu position Th transfe lengt specifie th lengt o th bloc t b writte (i bytes) Th requeste bloc lengt shal b withi th minimu an maximu bloc lengt rang (returne b th REA BLOC LIMIT command Sectio 9.2) I thi conditio i no met CHEC CONDITIO statu shal b returne an th sens ke shal b se t ILLEGA REQUES an n dat shal b written Upo successfu termination th mediu shal b positione afte th bloc writte b thi comman (end-of-mediu side). I th fixe bi i one th transfe lengt fiel specifie th numbe o block(s t b transferre t th logica uni beginnin a th curren mediu position Thi for o th WRIT comman i vali onl i th logica uni i currentl operatin i fixe bloc mod (se 9.3) Upo termination th mediu shal b positione afte th block(s writte b thi comman (end-of- mediu side) Th targe ma implemen fixe bloc mode variabl bloc mode o bot modes I th fixe bi doe no matc th curren mode o th mod indicate b th fixe bi i no implemented th targe shal rejec th comman b returnin CHEC CONDITIO statu an b settin th sens ke t ILLEGA REQUEST. I th earl warnin end-of-mediu conditio i encountere whil writing a attemp t finis writin an buffere dat ma b made Th comman shal terminat wit CHEC CONDITIO statu an th EO bi i extende sens shal b se t one I an dat remain i th target' buffer the th sens ke shal b se t VOLUM OVERFLOW I th fixe bi i on an th logica uni i no buffere (buffere mod o th MOD SENS comman i zero) the th vali bi i extende sens shal b se t on an th informatio byte shal b se t th differenc (residue betwee th requeste transfe lengt an th actua numbe o block writte t th medium I th fixe bi i on an th logica uni i buffere (buffere mod o th MOD SENS comman i one) the th vali bi shal b se t on an th informatio byte shal b se t th tota numbe o block no writte (th numbe o block no transferre fro th initiato plu th numbe o block remainin i th target' buffer) Not tha i thi cas i i possibl fo th valu i th informatio byte t excee th transfe length Whe th transfe lengt i zero n dat shal b transferre an th curren positio o th logica uni shal no b changed Thi conditio shal no b considere a a error. 9.5 TRACK SELECT Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 0BH Table 9-7 TRACK SELECT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Track Value | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th TRAC SELEC comman (Tabl 9-7 request tha th trac specifie i th trac valu field b selected. .pa 9.6 READ REVERSE Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 0FH Table 9-8 READ REVERSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Fixed | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA REVERS comman (Tabl 9-8 function identicall t th REA comman excep tha mediu motio i i th revers direction Thus th block(s an byte withi th block(s ar transferre i th revers orde an th mediu positio upo terminatio i befor th las bloc rea (beginning-of-mediu side) Thi comman shal terminat wit CHEC CONDITIO statu an th EO bi i extende sens shal b se t on i beginning-of-mediu o load-poin i encountered Th sens ke shal b se t N SENSE I th fixe bi i one the th vali bi shal b se t on an th informatio byte shal contai th differenc (residue o th requeste transfe lengt an th actua numbe o block transferre befor beginning-of-mediu o load-poin wa encountered. Filemar handlin i th sam a i th REA comman excep tha th mediu positio upo comman terminatio shal b befor th filemar (beginning-of- mediu side). I th transfe lengt i zero n dat shal b transferre an th curren positio o th logica uni shal no b changed Thi conditio shal no b considere a a error. Th targe ma implemen fixe bloc mode variabl bloc mode o bot modes I th fixe bi doe no matc th curren mode o th mod indicate b th fixe bi i no implemented th targe shal rejec th comman b returnin CHEC CONDITIO statu an b settin th sens ke t ILLEGA REQUEST. .pa 9.7 WRITE FILEMARKS Command Peripheral Device Type: Sequential Access Operation Code Type: Mandatory Operation Code: 10H Table 9-9 WRITE FILEMARKS Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Number of Filemarks (MSB) | -----|-----------------------------------------------------------------------| 3 | Number of Filemarks | -----|-----------------------------------------------------------------------| 4 | Number of Filemarks (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT FILEMARK comman (Tabl 9-9 cause th specifie numbe o filemark t b writte beginnin a th curren mediu positio o th logica unit zer i thi fiel indicate tha n filemark ar t b written. Thi comman i als use t forc an buffere dat (se buffere mod i th MOD SENS command Sectio 9.14 t b written Thi comman shal no retur GOO statu unles al buffere dat block an th filemark (i any ar correctl writte o th medium. I th earl warnin end-of-mediu conditio i encountere whil writing a attemp t finis writin an buffere dat ma b made Th comman shal terminat wit CHEC CONDITIO statu an th EO bi i extende sens shal b se t one I an filemark remai t b written the th sens ke shal b se t VOLUM OVERFLOW I th logica uni i no buffere (buffere mod o th MOD SENS comman i zero) the th vali bi i extende sens shal b se t on an th informatio byte shal b se t th numbe o unwritte filemarks I th logica uni i buffere (buffere mod o th MOD SENS comman i one) the th vali bi shal b se t on an th informatio byte shal b se t th tota numbe o block no writte (th numbe o unwritte filemark plu th numbe o block remainin i th target' buffer) Not tha i thi cas i i possibl fo th valu i th informatio byte t excee th transfe length. .pa 9.8 SPACE Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 11H Table 9-10 SPACE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Code | -----|-----------------------------------------------------------------------| 2 | Count (MSB) | -----|-----------------------------------------------------------------------| 3 | Count | -----|-----------------------------------------------------------------------| 4 | Count (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SPAC comman (Tabl 9-10 provide variet o positionin function tha ar determine b th cod an count Bot forwar (towar end-of- medium an revers (towar beginning-of-medium positionin ar provided althoug som SCS device ma onl suppor subse o thi command Suc SCS device shal retur CHEC CONDITIO statu an se th sens ke t ILLEGA REQUES i respons t an attemp t invok functio tha i no supported. The code is defined as follows: DB(1) DB(0) Description ----- ----- -------------------- 0 0 Blocks 0 1 Filemarks 1 0 Sequential Filemarks 1 1 Physical End-of-Data Whe spacin ove block o filemarks th coun fiel specifie th numbe o block o filemark t b space over positiv valu i th coun fiel shal caus forwar mediu movemen ove block o filemark endin o th end-of-mediu sid o th las bloc o filemark zer valu i th coun fiel shal caus n mediu movement negativ valu - (2' complemen notation i th coun fiel shal caus revers mediu movemen ove block o filemark endin o th beginning-of-mediu sid o th las bloc o filemark. I filemar i encountere whil spacin ove blocks mediu movemen shal b stopped Th mediu shal b positione o th end-of-mediu sid o th filemar i movemen wa i th forwar directio an o th beginning-of- mediu sid o th filemar i movemen wa i th revers direction CHEC CONDITIO statu shal b sen t th initiato an th filemar an vali bit i extende sens shal b se t one Th informatio byte shal b se t th differenc (residue i th requeste coun an th actua numbe o block space ove (no includin th filemark). I th physica end-of-mediu i encountere whil spacin forwar ove block o filemarks th targe shal retur CHEC CONDITIO statu t th initiato an shal se th end-of-mediu (EOM bi i extende sens t one Th sens ke shal b se t MEDIU ERROR Th targe shal se th vali bi t on an th informatio byte t th differenc (residue betwee th requeste coun an th actua numbe o block o filemark space over. I beginning-of-mediu o load-poin i encountere whil spacin ove block o filemark i th revers direction th targe shal retur CHEC CONDITIO statu t th initiato an shal se th end-of-mediu (EOM bi i extende sens t one Th sens ke shal b se t N SENSE Th targe shal se th vali bi t on an th informatio byte t th differenc (residue betwee th requeste coun an th actua numbe o block o filemark space over. Whe spacin ove sequentia filemarks th coun fiel i interprete a follows: (1 positiv valu shal caus forwar mediu movemen t th firs occurrenc o o mor consecutiv filemark stoppin afte th Nth filemark. (2 zer valu shal caus n mediu movement. (3 negativ valu - (2' complemen notation shal caus revers mediu movemen t th firs occurrenc o o mor consecutiv filemark stoppin o th beginning-of-mediu sid o th Nth filemark. Whe spacin t physica end-of-data th coun fiel i ignored Forwar mediu movemen shal occu unti th logica uni encounter physica end-of- dat a define b th sequential-acces device Som sequential-acces device defin physica end-of-dat a a erase are o th medium however othe definition ar no precluded Target tha implemen thi functio shal leav th mediu positione suc tha subsequen WRIT comman woul appen dat t th las recorde informatio o th medium. .pa 9.9 VERIFY Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 13H Table 9-11 VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BytCmp | Fixed | -----|-----------------------------------------------------------------------| 2 | Verification Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Verification Length | -----|-----------------------------------------------------------------------| 4 | Verification Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th VERIF comman (Tabl 9-11 verifie on o mor block(s beginnin wit th nex bloc o th logica unit Th fixe bi specifie bot th meanin o th verificatio lengt fiel an whethe fixed-lengt o variable-lengt block(s ar t b verified. byt compar (BytCmp bi o zer indicate tha th verificatio shal b simpl mediu verificatio (CRC ECC etc) N dat shal b transferre betwee th initiato an target byt compar bi o on indicate tha byte-by-byt compar o th dat o th medium an th dat transferre fro th initiato shal b performe b th target Dat shal b transferre fro th initiato t th targe a i WRIT command. fixe bi o zer request tha th nex bloc o th logica uni b verified Th verificatio lengt specifie th numbe o byte t verify fixe bi o on request verificatio lengt block b verifie beginnin wit th nex logica bloc o th logica unit Thi for o th VERIF comman i onl vali i th logica uni i currentl i fixe bloc mod a define i th REA command I th dat doe no compar (byt compar bi equal one) th comman shal terminat wit CHEC CONDITIO statu an th sens ke shal b se t MISCOMPARE I th fixe bi i one th vali bi shal b se t on an th informatio byte shal b se t th differenc (residue betwee th verificatio lengt an th actua numbe o block successfull verified Th mediu shal b positione afte th bloc containin th miscompar (end-of-mediu side). Th targe ma implemen fixe bloc mode variabl bloc mode o bot modes I th fixe bi doe no matc th curren mode o th mod indicate b th fixe bi i no implemented th targe shal rejec th comman b returnin CHEC CONDITIO statu an b settin th sens ke t ILLEGA REQUEST. Th VERIFY comman shal terminat whe th verificatio lengt ha bee satisfied whe filemar i encountered o whe physica end-of-mediu i encountered Th statu an sens dat fo eac o thes condition ar handle th sam a i th REA command Upo completio o th VERIFY command th mediu shal b positione afte th las bloc fro whic dat wa verifie o afte th filemark i encountered Whe th verificatio lengt i zero n dat shal b verifie an th curren positio o th logica uni shal no b changed Thi conditio shal no b considere a a error. 9.10 RECOVER BUFFERED DATA Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 14H Table 9-12 RECOVER BUFFERED DATA Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Fixed | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RECOVE BUFFERE DAT comman (Tabl 9-12 i use t rea dat tha ha bee transferre t a SCS devic buffe bu ha no bee writte o th medium I i normall onl use t recove fro erro o exceptio condition tha mak i impossibl t writ th buffere dat o th medium Thi comman function similarl t th REA comman excep tha th dat i transferre fro th SCS devic buffe instea o th medium Th orde i whic block(s ar transferre i th sam a i the woul hav bee transferre t th medium On o mor RECOVE BUFFERE DAT command ma b use t rea th unwritte buffere data. Th targe ma implemen fixe bloc mode variabl bloc mode o bot modes I th fixe bi doe no matc th curren mode o th mod indicate b th fixe bi i no implemented th targe shal rejec th comman b returnin CHEC CONDITIO statu an b settin th sens ke t ILLEGA REQUEST. I a attemp i mad t recove mor logica block o dat tha ar containe i th SCS devic buffer th comman shal b terminate wit CHEC CONDITIO status Th EO bi i extende sens shal b se t one I th fixe bi i one th vali bi shal b se t on an th informatio byte shal b se t th differenc (residue betwee th requeste transfe lengt an th actua numbe o block transferred. Th transfe lengt specifie th numbe o contiguou logica block o dat t b transferred transfe lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error. 9.11 MODE SELECT Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 15H Table 9-13 MODE SELECT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SELEC comman (Tabl 9-13 provide mean fo th initiato t specif medium logica unit o periphera devic parameter t th target Th paramete lis lengt specifie th lengt i byte o th MOD SELEC paramete lis tha shal b transferre durin th DAT OU phase zer paramete lis lengt indicate tha n dat shal b transferred Thi conditio shal no b considere a a error. Th MOD SELEC paramete lis show i Tabl 9-1 contain fou-byt header followe b zer o mor eight-byt bloc descriptors followe b th vendo uniqu parameters i any. .pa Table 9-14 MOD SELEC Parameter List ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 |Reserved| Buffered Mode | Speed | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Bloc Descripto(s) | ============================================================================== 0 | Density Code | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== buffere mod o zer indicate tha th targe shal no repor a GOO statu o WRIT command unti th dat block ar actuall writte o th medium buffere mod o on indicate tha th targe ma repor a GOO statu o WRIT command a soo a th dat bloc ha bee transferre t th SCS devic buffer On o mor block ma b buffere prio t writin th block(s t th medium Buffere mode o 2H throug 7H ar reserved. Code values for the speed field shall be assigned as follows: 0H Default (Use the peripheral device's default speed). 1H Use the peripheral device's lowest speed. 2H _ FH Use increasing peripheral device speeds. Th bloc descripto lengt specifie th lengt i byte o al th bloc descriptors I i equa t th numbe o bloc descriptor time eight and doe no includ th vendo uniqu parameters i any bloc descripto lengt o zer indicate tha n bloc descriptor ar include i th paramete list Thi conditio shal no b considere a a error. Eac bloc descripto specifie th mediu characteristic fo al o par o logica unit Eac bloc descripto contain densit code numbe o blocks an bloc length. Code values for the density code field are defined in Table 9-14.1. Table 9-14.1 Sequential-access Density Codes ============================================================================== Code Value Density ---------- ------------------------------------------------------------------ 00H Default (peripheral device's default or only density) Magnetic Tapes Width Density Reference mm. (Inch) Tracks BPMM (BPI) Code Type Standard Note ---------- ------ ------------ ---- ---- ------------ ---- 01H 12.7 (0.5) 9 32 (800) NRZI R X3.22-1983 3 02H 12.7 (0.5) 9 63 (1 600) PE R X3.39-1973 3 03H 12.7 (0.5) 9 246 (6 250) GCR R X3.54-1976 3 04H 6.3 (0.25) 4/9 315 (8 000) GCR C 2,4 05H 6.3 (0.25) 4/9 315 (8 000) GCR C X3.136-198X 2 06H 12.7 (0.5) 9 126 (3 200) PE R X3B5/85-98 1,3 07H 6.3 (0.25) 4 252 (6 400) IMFM C X3.116-198X 2 08H 3.81 (0.15) 4 315 (8 000) GCR CS X3B5/85-77 1,2 09H 12.7 (0.5) 18 C X3B5/85-76 1,3 0AH 12.7 (0.5) 22 267 (6 667) MFM C 2 0BH 6.3 (0.25) 4 63 (1 600) PE C X3.56-198X 2 0CH 12.7 (0.5) 24 500 (12 690) GCR C 2 0DH 12.7 (0.5) 24 999 (25 380) GCR C 2 80H _ FFH Vendor unique All others Reserved ============================================================================== Key: Code Type -------------------------------------------- ----------------------- NRZI Non Return to Zero, change on ones R Reel-to-Reel GCR Group Code Recording C Cartridge PE Phase Encoded CS Cassette IMFM Inverted Modified Frequency Modulation NOTES: (1 Workin Draft X3B assign ne documen numbe t eac revisio o thei documents Pleas contac th Chairma o X3B fo th lates documen number. (2) Serially Recorded. (3) Parallel Recorded. (4) Old format known as QIC-11. Th numbe o block fiel specifie th numbe o logica block on th mediu tha mee th densit cod an bloc lengt i th bloc descriptor numbe o block o zer indicate tha al o th remainin logica block o th logica uni shal hav th mediu characteristic specifie b th bloc descriptor. Th bloc lengt specifie th lengt i byte o eac logica bloc describe b th bloc descriptor bloc lengt o zer indicate tha th length shall be variable. .fo Section 9 132.1 .pa .fo Section 9 132.2 9.12 RESERVE UNIT and RELEASE UNIT Commands Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 16H and 17H, respectively Table 9-15 RESERVE UNIT and RELEASE UNIT Commands ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | 3rdPty | Third Party Device ID |Reserved| -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RESERV UNI an RELEAS UNI command bot us th comman descripto block shown in Table 9-15. 9.12. RESERV UNI Command. Th RESERV UNI comman (Tabl 9-15 operatio cod 16H shal reserv th specifie logica uni fo th exclusiv us b th requestin initiato or i third-part reservatio optio i implemented, to another specified SCSI device. Th reservatio shal remai i effec unti supercede b anothe RESERV UNI comman fro th initiato tha mad th reservatio o unti release b RELEAS UNI comman fro th sam initiator o BU DEVIC RESE messag fro an initiator o "hard RESE condition Th occurrenc o th las tw condition i indicate b sens ke o UNI ATTENTIO o th nex comman followin th condition I i no a erro t issu thi comman t logica uni tha i currentl reserve t th requestin initiator. I th logica uni i previousl reserve by anothe initiator the th targe shal either: (1 retur RESERVATIO CONFLIC status (2 queu th reservatio reques an disconnec unti al previousl queue reservation hav bee released Whe th logica uni i available th targe shal reconnec t perfor th reservation If afte honorin th reservation an othe initiato the subsequentl attempt t perfor an comman o th reserve logica uni othe tha RESERV UNI command whic ma b queued o RELEAS UNI command whic shal b ignored the th comman shal b rejecte wit RESERVATIO CONFLIC status .pn 133 .fo Section 9 # Th third-part reservatio optio fo th RESERV UNI comman allow a initiato t reserv logica uni fo anothe SCS device Thi optio i intende fo us i multiple-initiato system tha us th COP command An targe tha implement th third-part reservatio optio shal als implemen th third-part releas optio (se 9.12.2). I th third-part (3rdPty bi i zero the th third-part reservatio optio i no requested I th 3rdPt bi i on an th third-part reservatio optio i implemented the th RESERV UNI comman shal reserv th specifie logica uni fo th SCS devic specifie i th third-part devic I field Th targe shal preserv th reservatio unti supercede b anothe RESERV UNI comman fro th initiato tha mad th reservatio o unti release b th sam initiator b BU DEVIC RESE messag fro an initiator o b "hard RESE condition Th targe shal ignor (i.e. retur GOO status an attemp mad b an othe initiato t releas th reservation. I th 3rdPt bi i on an th third-part reservatio optio i no implemented the th targe shal rejec th RESERV UNI comman wit CHEC CONDITIO statu an sens ke o ILLEGA REQUEST A initiato tha hold curren reservatio ma modif tha reservatio (e.g. switc third-parties b issuin anothe RESERV UNI comman t th sam logica unit Th supercedin RESERV UNI comman shal releas th previou reservatio stat onl whe th ne reservatio i granted supercedin reservatio take priorit ove an previousl queue reservatio request. 9.12. RELEAS UNI Command. Th RELEAS UNI comman (Tabl 9-15 operatio cod 17H shal releas th logica uni i i i currentl reserve by th requestin initiator I i no a erro t attemp t releas logica uni tha i no currentl reserve t th requestin initiator However i shal no b release i i i reserve b anothe initiator. Th third-part releas optio fo th RELEAS UNI comman allow a initiato t releas logica uni tha wa previousl reserve usin th third-part reservatio optio (se 9.12.1) Thi optio shal b implemente i th third-part reservatio optio i implemented Thi optio i intende fo us i multiple-initiato system tha us th COP command. I th third-part (3rdPty bi i zero the th third-part releas optio i no requested I th 3rdPt bi i on an th targe implement th third-part releas option the th targe shal releas th specifie logica unit bu onl i th reservatio wa mad usin th third-part reservatio optio b th initiato tha i requestin th releas an fo th sam SCS devic a specifie i th third-part devic I field. I th 3rdPt bi i on an th targe doe no implemen th third-part releas option the th targe shal terminat th comman wit CHEC CONDITIO statu an th sens ke shall be se t ILLEGA REQUEST. .pa 9.13 ERASE Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 19H Table 9-16 ERASE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Long | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th ERAS comman (Tabl 9-16 cause par o al o th remainin mediu t b erase beginnin fro th curren mediu position A use here "erased mean eithe th mediu shal b erase o patter shal b writte o th mediu tha appear a ga t th target Th distanc t b erase i controlle b th lon bit lon bi o on indicate tha al remainin mediu o th logica uni shal b erased lon bi o zer indicate tha periphera devic specifie portio o th mediu shal b erased Normally shor erase ar use t creat a extende ga fo softwar controlle erro recover o fo suppor o "updat i place functions Th mediu positio followin a ERAS comman wit lon bi o one is not defined by this standard. NOTE Som target ma rejec ERAS command wit th lon bi se t on i th mediu i no positione a the beginning-of-medium. .pa 9.14 MODE SENSE Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 1AH Table 9-17 MODE SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Lengt | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SENS comman (Tabl 9-17 provide mean fo targe t repor it medium logica unit o periphera devic parameter t th initiator I i complementar comman t th MOD SELEC comman (se 9.11 fo suppor o mediu tha ma contai differen densities suc a half-inc tapes. Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo returne MOD SENS data A allocatio lengt o zer indicate tha n MOD SENS dat shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl MOD SENS dat have bee transferre t th initiator, whichever is less Th MOD SENS dat (Tabl 9-18 contain four-byt header followe b zer o mor eight-byt bloc descriptors followe b th vendo uniqu parameters i any. .pa Table 9-18 MOD SENS Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Sense Data Length | -----|-----------------------------------------------------------------------| 1 | Medium Type | -----|-----------------------------------------------------------------------| 2 | WP | Buffered Mode | Speed | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Bloc Descripto(s) | ============================================================================== 0 | Density Code | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== Th sens dat lengt specifie th lengt i byte o th followin mod sens dat tha i availabl t b transferre durin th DAT I phase Th sense data length does not include itself. Code values for the medium type field shall be assigned as follows: 00H Default (Only one medium type supported) 01H _ 7FH Reserved 80H _ FFH Vendor unique writ protecte (WP bi o zer indicate tha th mediu i writ enabled writ protecte bi o on indicate tha th mediu i writ protected. buffere mod o zer indicate tha th targe does no repor a GOO statu o WRIT command unti th dat block ar actuall writte o th medium buffere mod o on indicate tha th targe ma repor a GOO statu o WRIT command a soo a th dat bloc ha bee transferre t th SCS devic buffer On o mor block ma b buffere prio t writin th block(s t th medium Buffere mode o 2H throug 7H ar reserved. Code values for the speed field shall be assigned as follows: 0H Default (only one speed supported) 1H Lowest peripheral device speed 2H _ FH Increasing peripheral device speeds Th bloc descripto lengt specifie th lengt i byte o al th bloc descriptors I i equa t th numbe o bloc descriptor time eight and doe no includ th vendo uniqu parameters i any bloc descripto lengt o zer indicate tha n bloc descriptor shal b include i th paramete list Thi conditio shal no b considere a a error. Eac bloc descripto specifie th mediu characteristic fo al o par o logica unit Eac bloc descripto contain densit code numbe o blocks an bloc length. Code values for the density code field are defined in Table 9-14.1. Th numbe o block fiel specifie th numbe o logica block on th mediu tha mee th densit cod an bloc lengt i th bloc descriptor numbe o block o zer indicate tha al o th remainin logica block o th logica uni hav th mediu characteristic specifie b th bloc descriptor. Th bloc lengt specifie th lengt i byte o eac logica bloc describe b th bloc descriptor bloc lengt o zer indicate tha th length is variable. .pa 9.15 LOAD/UNLOAD Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 1BH Table 9-19 LOAD/UNLOAD Command  ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Immed | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | Re-Ten | Load | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th LOAD/UNLOA comman (Tabl 9-19 request tha th targe enabl o disabl th logica uni fo furthe operations Thi comman ma als b use t reques th re-tensio functio o periphera device tha suppor thi function. loa bi o on indicate tha th mediu o th logica uni shal b loade an positione t th beginning-of-mediu o load-poin a determine b th periphera device loa bi o zer indicate tha th mediu o th logica uni shal b positione fo remova fro th periphera device. Statu shal b returne afte th mediu i positione unles th immediat (Immed bi i one I th Imme bi i one statu ma b returne a soo a th comman ha bee accepted. re-tensio (Re-Ten bi o on indicate tha th mediu o th addresse logica uni shal b correctl tensione befor th LOAD/UNLOA comman i completed Thi i a optiona functio intende fo us b thos periphera device tha suppor th re-tensio function. .pa 9.16 PREVENT/ALLOW MEDIUM REMOVAL Command Peripheral Device Type: Sequential Access Operation Code Type: Optional Operation Code: 1EH Table 9-20 PREVENT/ALLOW MEDIUM REMOVAL Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | Prevent| -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th PREVENT/ALLO MEDIU REMOVA comman (Tabl 9-20 request tha th targe enabl o disabl th remova o th mediu i th logica unit. preven bi o on shal inhibi mechanism tha normall allo remova o th medium preven bi o zer shal allo remova o th medium. Thi preventio o mediu remova conditio shal terminat upo receip o PREVENT/ALLO MEDIU REMOVA comman wit th preven bi se t zero o b th receip o BU DEVIC RESE messag fro an initiato o b "hard RESE condition. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 10 # 10. Group 0 Command Descriptions for Printer Devices The Group 0 commands for printer devices shall be as shown in Table 10-1. Table 10-1 Group 0 Commands for Printer Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H V 02H V 03H M REQUEST SENSE 7.1.2 04H O FORMAT 10.1 05H V 06H V 07H V 08H V 09H V 0AH M PRINT 10.2 0BH O SLEW AND PRINT 10.3 0CH V 0DH V 0EH V 0FH V 10H O FLUSH BUFFER 10.4 11H V 12H E INQUIRY 7.1.3 13H V 14H O RECOVER BUFFERED DATA 10.5 15H O MODE SELECT 10.6 16H O RESERVE UNIT 10.7.1 17H O RELEASE UNIT 10.7.2 18H O COPY 7.1.4 19H V 1AH O MODE SENSE 10.8 1BH O STOP PRINT 10.9 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH R 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 10.1 FORMAT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 04H Table 10-2 FORMAT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Format Type | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th FORMA comman (Tabl 10-2 provide mean fo th initiato t specif form o font t printer tha suppor programmabl form o fonts Th forma informatio sen i vendo uniqu sinc i i peripheral-devic specific. Th forma typ fiel specifie th typ o forma informatio t b transferre fro th initiato t th target Thi fiel i define a follows: DB(1) DB(0) Format Type ----- ----- ------------- 0 0 Set Form 0 1 Set Font 1 0 Vendor Unique 1 1 Reserved Th transfe lengt specifie th lengt i byte o forma informatio tha shal b sen durin th DAT OU phase transfe lengt o zer indicate tha n forma informatio shal b sent Thi conditio shal no b considere a a error. .pa 10.2 PRINT Command Peripheral Device Type: Printer Operation Code Type: Mandatory Operation Code: 0AH Table 10-3 PRINT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th PRIN comman (Tabl 10-3 transfer th specifie numbe o byte fro th initiato t th targe t b printed Th dat sen i applicatio dependent. Th transfe lengt specifie th lengt i byte o dat tha shal b sen durin th DAT OU phase transfe lengt o zer indicate tha n dat shal b sent Thi conditio shal no b considere a a error .pa 10.3 SLEW AND PRINT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 0BH Table 10-4 SLEW AND PRINT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logica Uni Numbe Reserved Channel| -----|-----------------------------------------------------------------------| 2 | Slew Value | -----|-----------------------------------------------------------------------| 3 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SLE AN PRIN comman (Tabl 10-4 transfer th specifie numbe o byte fro th initiato t th targe t b printed Th dat sen i applicatio dependent Thi comman i provide fo printer tha d no suppor form contro informatio imbedde withi th prin data Th transfe lengt specifie th lengt i byte o dat tha shal b sen durin th DAT OU phase transfe lengt o zer indicate tha n dat shal b sent Thi conditio shal no b considere a a error I th channe bi i zero th sle valu specifie th numbe o line th for shal b advance befor printing valu o 25 indicate tha th for shal b advance t th firs lin o th nex for befor printing I th channe bi i one th sle valu specifie th form contro channe numbe t whic th for shal b advance prio t printin th data. I th channe bi i one an th channe optio i no implemented th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shall be se t ILLEGA REQUEST. .pa 10.4 FLUSH BUFFER Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 10H Table 10-5 FLUSH BUFFER Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logica Uni Numbe Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th FLUS BUFFE comman (Tabl 10-5 provide mean fo a initiato t ensur tha th dat have bee successfull printe prio t releasin th periphera device Thi i usefu fo application tha wis t handl an erro o exceptio condition (e.g. end-of-medium prio t terminatio o the application. Whe al buffere dat ar actuall printe th comman shal b terminate wit a GOO status I i i no possibl t finis printin al o th buffere dat (du t a erro o exceptio conditio o th periphera device) the thi comman shal b terminate wit CHEC CONDITIO statu an th appropriat sens key. .pa 10.5 RECOVER BUFFERED DATA Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 14H Table 10-6 RECOVER BUFFERED DATA Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logica Uni Numbe Reserved | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RECOVE BUFFERE DAT comman (Tabl 10-6 return t th initiato th dat tha ha bee sen t th target bu no ye printed Thi comman i normall use onl t recove fro erro o exceptio condition tha mak i impossibl t prin th buffere data Th orde i whic th dat i transferre fro th targe t th initiato i th sam a i wa whe th dat wa previousl transferre usin th PRIN comman o SLE AN PRIN command Dat tha i transferre b thi comman i delete fro th targe dat buffer On o mor RECOVE BUFFERE DAT command ma b use t retur th unprinte buffere data. I a attemp i mad t recove mor dat tha i containe i th buffer th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t N SENSE I addition th EOM th valid an th IL bit i extende sens shal b se t one Th informatio byte shal b se t th differenc (residue betwee th transfe lengt an th actua numbe o byte returned Th transfe lengt specifie th maximu lengt i byte o dat tha shal b transferre durin th DAT I phase transfe lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error. .pa 10.6 MODE SELECT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 15H Table 10-7 MODE SELECT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logica Uni Numbe Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SELEC comman (Tabl 10-7 provide mean fo th initiato t specif medium logica unit o periphera devic parameter t th target. Th paramete lis lengt specifie th lengt i byte o th MOD SELEC paramete lis tha shal b transferre durin th DAT OU phase paramete lis lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error Th MOD SELEC paramete lis (Tabl 10-8 contain four-byt header followe b th vendo uniqu parameters i any. Table 10-8 MOD SELEC Parameter List ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 |Reserved| Buffered Mode | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== buffere mod o zer indicate tha th targe shal no repor a GOO statu o PRIN command o SLE AN PRIN command unti th dat ar actuall printed buffere mod o on indicate tha th targe ma repor a GOO statu o PRIN command o SLE AN PRIN command a soo a th dat hav bee transferre t th SCS devic buffer Th dat fro on o mor command ma b buffere prio t printing Buffere mode o 2H throug 7H ar reserved. 10.7 RESERVE UNIT and RELEASE UNIT Commands Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 16H and 17H, respectively Table 10-9 RESERVE UNIT and RELEASE UNIT Commands ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | 3rdPty | Third Party Device ID |Reserved| -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RESERV UNI an RELEAS UNI command bot us th comman descripto block shown in Table 10-9. 10.7.1 RESERV UNI Command. Th RESERV UNI comman (Tabl 10-9 operatio cod 16H shal reserv th specifie logica uni fo th exclusiv us b th requestin initiato or i third-part reservatio optio i implemented, to another specified SCSI device. Th reservatio shal remai i effec unti supercede b anothe RESERV UNI comman fro th initiato tha mad th reservatio o unti release b RELEAS UNI comman fro th sam initiator o BU DEVIC RESE messag fro an initiator o "hard RESE condition Th occurrenc o th las tw condition i indicate b sens ke o UNI ATTENTIO o th nex comman followin th condition I i no a erro t issu thi comman t logica uni tha i currentl reserve t th requestin initiator. I th logica uni i previousl reserve by anothe initiator the th targe shal either: (1 retur RESERVATIO CONFLIC status (2 queu th reservatio reques an disconnec unti al previousl queue reservation hav bee released Whe th logica uni i available th targe shal reconnec t perfor th reservation If afte honorin th reservation an othe initiato the subsequentl attempt t perfor an comman o th reserve logica uni othe tha RESERV UNI command whic ma b queued o RELEAS UNI command whic shal b ignored the th comman shal b rejecte wit RESERVATIO CONFLIC status Th third-part reservatio optio fo th RESERV UNI comman allow a initiato t reserv logica uni fo anothe SCS device Thi optio i intende fo us i multiple-initiato system tha us th COP command An targe tha implement th third-part reservatio optio shal als implemen th third-part releas optio (se 10.7.2). I th third-part (3rdPty bi i zero the th third-part reservatio optio i no requested I th 3rdPt bi i on an th third-part reservatio optio i implemented the th RESERV UNI comman shal reserv th specifie logica uni fo th SCS devic specifie i th third-part devic I field Th targe shal preserv th reservatio unti supercede b anothe RESERV UNI comman fro th initiato tha mad th reservatio o unti release b th sam initiator b BU DEVIC RESE messag fro an initiator o b "hard RESE condition Th targe shal ignor (i.e. retur GOO status an attemp mad b an othe initiato t releas th reservation. I th 3rdPt bi i on an th third-part reservatio optio i no implemented the th targe shal rejec th RESERV UNI comman wit CHEC CONDITIO statu an sens ke o ILLEGA REQUEST A initiato tha hold curren reservatio ma modif tha reservatio (e.g. switc third-parties b issuin anothe RESERV UNI comman t th sam logica unit Th supercedin RESERV UNI comman shal releas th previou reservatio stat onl whe th ne reservatio i granted supercedin reservatio take priorit ove an previousl queue reservatio request. 10.7. RELEAS UNI Command. Th RELEAS UNI comman (Tabl 10-9 operatio cod 17H shal releas th logica uni i i i currentl reserve by th requestin initiator I i no a erro t attemp t releas logica uni tha i no currentl reserve t th requestin initiator However i shal no b release i i i reserve b anothe initiator. Th third-part releas optio fo th RELEAS UNI comman allow a initiato t releas logica uni tha wa previousl reserve usin th third-part reservatio optio (se 10.7.1) Thi optio shal b implemente i th third-part reservatio optio i implemented Thi optio i intende fo us i multiple-initiato system tha us th COP command. I th third-part (3rdPty bi i zero the th third-part releas optio i no requested I th 3rdPt bi i on an th targe implement th third-part releas option the th targe shal releas th specifie logica unit bu onl i th reservatio wa mad usin th third-part reservatio optio b th initiato tha i requestin th releas an fo th sam SCS devic a specifie i th third-part devic I field. I th 3rdPt bi i on an th targe doe no implemen th third-part releas option the th targe shal terminat th comman wit CHEC CONDITIO statu an th sens ke shall be se t ILLEGA REQUEST. 10.8 MODE SENSE Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 1AH Table 10-10 MODE SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logica Uni Numbe Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SENS comman (Tabl 10-10 provide mean fo targe t repor it medium logica unit o periphera devic parameter t th initiator I i complementar comman t th MOD SELEC command. Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo returne MOD SENS data A allocatio lengt o zer indicate tha n MOD SENS dat shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl MOD SENS dat hav bee transferre t th initiator, whichever is less Th MOD SENS dat (Tabl 10-11 contain four-byt header followe th vendo uniqu parameters i any. .pa Table 10-11 MOD SENS Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Sense Data Length | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 |Reserved| Buffered Mode | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== Th sens dat lengt specifie th lengt i byte o th followin MOD SENS dat tha i availabl t b transferre durin th DAT I phase Th sense data length does not include itself. buffere mod o zer indicate tha th targe doe no repor a GOO statu o PRIN command o SLE AN PRIN command unti th dat ar actuall printed buffere mod o on indicate tha th targe ma repor a GOO statu o PRIN command o SLE AN PRIN command a soo a th dat hav bee transferre t th SCS devic buffer Th dat fro on o mor command ma b buffere prio t printing Buffere mode o 2H throug 7H ar reserved. .pa 10.9 STOP PRINT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 1BH Table 10-12 STOP PRINT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logica Uni Numbe Reserved | Retain | -----|-----------------------------------------------------------------------| 2 | Vendor Unique | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th STO PRIN comman (Tabl 10-12 i use t hal printin o buffere device i a orderl fashion retai bi o zer request tha th targe dat buffe b discarded otherwise th unprinte dat i retained Th unprinte dat ma b recovere b us o th RECOVE BUFFERE DAT command i supported subsequen PRIN comman o SLE AN PRIN comman shal caus th remainin unprinte an unrecovere dat t b printe followe b th dat transferre b th subsequen command Th poin a whic printin i suspende b thi comman i peripheral-devic specifi an i no define b thi standard. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 11 # 11. Group 0 Command Descriptions for Processor Devices The Group 0 commands for processor devices shall be as shown in Table 11-1. Table 11-1 Group 0 Commands for Processor Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H V 02H V 03H M REQUEST SENSE 7.1.2 04H V 05H V 06H V 07H V 08H O RECEIVE 11.1 09H V 0AH M SEND 11.2 0BH V 0CH V 0DH V 0EH V 0FH V 10H V 11H V 12H E INQUIRY 7.1.3 13H V 14H V 15H V 16H V 17H V 18H O COPY 7.1.4 19H R 1AH R 1BH R 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH R 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 11.1 RECEIVE Command Peripheral Device Type: Processor Devices Operation Code Type: Optional Operation Code: 08H Table 11-2 RECEIVE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Allocation Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Allocation Length | -----|-----------------------------------------------------------------------| 4 | Allocation Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th RECEIV comman (Tabl 11-2 transfer dat fro th targe t th initiato. Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo th returne data A allocatio lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl dat hav bee transferre t th initiator whicheve i less. .pa 11.2 SEND Command Peripheral Device Type: Processor Devices Operation Code Type: Mandatory Operation Code: 0AH Table 11-3 SEND Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th SEN comman (Tabl 11-3 transfer dat fro th initiato t th targe. Th transfe lengt specifie th lengt i byte o dat tha shal b sen durin th DAT OU phase transfe lengt o zer indicate tha n dat shal b sent Thi conditio shal no b considere a a error. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 12 # 12. Command Descriptions for Write-Once Read-Multiple Devices 12. Grou Command fo Write-Onc Read-Multipl Devices. Th Grou command fo write-onc read-multipl device shal b a show i Tabl 12-1. Table 12-1 Group 0 Commands for Write-Once Read-Multiple Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H O REZERO UNIT 8.1.1 02H V 03H M REQUEST SENSE 7.1.2 04H R 05H V 06H V 07H O REASSIGN BLOCKS 8.1.3 08H O READ 12.1.1 09H V 0AH O WRITE 12.1.2 0BH O SEEK 8.1.6 0CH V 0DH V 0EH V 0FH V 10H V 11H V 12H E INQUIRY 7.1.3 13H V 14H V 15H O MODE SELECT 12.1.3 16H O RESERVE 8.1.8 17H O RELEASE 8.1.9 18H O COPY 7.1.4 19H V 1AH O MODE SENSE 12.1.4 1BH O START/STOP UNIT 8.1.11 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH O PREVENT/ALLOW MEDIUM REMOVAL 8.1.12 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 12.1.1 READ Command Periphera Devic Type Writ-Once Read-Multiple and Read-Onl Direc Access Operation Code Type: Optional Operation Code: 08H Table 12-2 READ Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA comman (Tabl 12-2 request tha th targe transfe dat t th initiator. Th logica bloc addres specifie th logica bloc a whic th rea operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat t b transferred Transfe Lengt o zer indicate tha 25 logica block shal b transferred An othe valu indicate th numbe o logica block tha shal b transferred. Thi comman shal b terminate wit statu o RESERVATIO CONFLIC i an reservatio acces conflic (se 8.1.8 exist an n dat shal b transferred. I an o th followin condition occur thi comman shal b terminate wit CHEC CONDITIO status an i extende sens i implemented th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus the CHEC CONDITIO status. .pa Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Unrecoverable read error MEDIUM ERROR Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to read a blank or previously unwritten block BLANK CHECK (see note 2) NOTES: (1 Th extende sens informatio byte shal b se t th logica bloc addres o th firs invali address (2 Th extende sens informatio byte shal b se t th logica bloc addres o th firs blan bloc encountered Th dat rea u t tha bloc shal b transferred 12.1.2 WRITE Command Peripheral Device Type: Write-Once Read-Multiple Operation Code Type: Optional Operation Code: 0AH Table 12-3 WRITE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT comman (Tabl 12-3 request tha th targe writ th dat transferre from th initiato t th medium Th logica bloc addres specifie th logica bloc a whic th writ operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat tha shal b written transfe lengt o zer indicate tha 25 logica block shal b written An othe valu indicate th numbe o logica block tha shal b written. Thi comman shal b terminate wit statu o RESERVATIO CONFLIC i an reservatio acces conflic (se 8.1.8 exist an n dat shal b written. I an o th followin condition occur thi comman shal b terminate wit CHEC CONDITIO status an i extende sens i implemented th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus the CHEC CONDITIO status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to write a previously written block and blank checking is enabled (see 12.1.3) BLANK CHECK (see note 2) NOTES: (1 Th extende sens informatio byte shal b se t th logica Bloc Addres o th firs invali address (2 Th extende sens informatio byte shal b se t th logica bloc addres o th firs non-blan bloc encountered .pa 12.1.3 MODE SELECT Command Periphera Devic Type Writ-Once Read-Multiple and Read-Onl Direc Access Operation Code Type: Optional Operation Code: 15H Table 12-4 MODE SELECT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SELEC comman (Tabl 12-4 provide mean fo th initiato t specif medium logica unit o periphera devic parameter t th target Th paramete lis lengt specifie th lengt i byte o th MOD SELEC paramete lis tha shal b transferre fro th initiato t th target paramete lis lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error. Th MOD SELEC paramete lis (Tabl 12-5 contain four-byt header followe b zer o mor eight-byt bloc descriptors followe b th vendo uniqu parameters i any. .pa Table 12-5 MOD SELEC Parameter List ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | EBC | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Bloc Descriptor(s | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== A enabl blan chec (EBC bi o zer disable blan checkin o th mediu durin writ operations A EB bi o on enable blan checking I non-blan bloc i foun durin writ operation th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t BLAN CHECK Fo read-onl direct-acces devices th EB bi i reserved. Th bloc descripto lengt specifie th lengt i byte o al th bloc descriptors I i equa t th numbe o bloc descriptor time eight and doe no includ th vendo uniqu parameters i any bloc descripto lengt o zer indicate tha n bloc descriptor shal b include i th paramete list Thi conditio shal no b considere a a error. Eac bloc descripto specifie th mediu characteristic fo al o par o logica unit Eac bloc descripto contain numbe o block an bloc length Th numbe o block fiel specifie th numbe o logica block t b formatte wit th bloc lengt specifie i th bloc descriptor Th bloc lengt fiel specifie th lengt i byte o th logica bloc t b formatted. 12.1.4 MODE SENSE Command Periphera Devic Type Writ-Once Read-Multiple and Read-Onl Direc Access Operation Code Type: Optional Operation Code: 1AH Table 12-6 MODE SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th MOD SENS comman (Tabl 12-6 provide mean fo targe t repor it medium logica unit o periphera devic parameter t th initiator I i complementar comman t th MOD SELEC comman fo suppor o mediu tha ma contai multipl bloc lengths. Th allocatio lengt specifie th numbe o byte tha th initiato ha allocate fo returne MOD SENS Data A allocatio lengt o zer indicate tha n MOD SENS dat shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th maximu numbe o byte tha shal b transferred Th targe shal terminat th DAT I phas whe allocatio lengt byte hav bee transferre o whe al availabl MOD SENS dat hav bee transferre t th initiator whicheve i less. Th MOD SENS dat (Tabl 12-7 contain four-byt header followe b zer o mor eight-byt bloc descriptors followe b th vendo uniqu parameters i any. .pa Table 12-7 MOD SENS Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Sense Data Length | -----|-----------------------------------------------------------------------| 1 | Medium Type | -----|-----------------------------------------------------------------------| 2 | WP | Reserved | EBC | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Bloc Descriptor(s | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== Th sens dat lengt specifie th lengt i byte o th followin MOD SENS dat tha i availabl t b transferre durin th DAT I phase Th sense data length does not include itself. Code values for the medium type field shall be assigned as follows: 00H Default (only one medium type supported) 01H _ 7FH Reserved 80H _ FFH Vendor unique A enabl blan chec (EBC bi o zer indicate tha blan checkin o th mediu durin writ operation i disabled A EB bi o on indicate tha blan checkin durin writ operation i enabled Fo read-onl direct- acces devices th EB bi i reserved. writ protecte (WP bi o zer indicate tha th mediu i writ enabled W bi o on indicate tha th mediu i writ protected Fo read-onl direct-acces devices th W bi i reserved. Th bloc descripto lengt specifie th lengt i byte o al th bloc descriptors I i equa t th numbe o bloc descriptor time eight and doe no includ th vendo uniqu parameters i any bloc descripto lengt o zer indicate tha n bloc descriptor shal b include i th paramete list Thi conditio shal no b considere a a error. Eac bloc descripto specifie th mediu characteristic fo al o par o logica unit Eac bloc descripto contain numbe o block an bloc length. Th numbe o block fiel indicate th numbe o logica block tha hav th bloc lengt specifie i th bloc descriptor Th bloc lengt fiel indicate th lengt i byte o each logica block. .pa ?? 12. Grou Command fo Write-Onc Read-Multipl Devices. Th Grou command fo write-onc read-multipl device shal b a show i Tabl 12-8. Table 12-8 Group 1 Commands for Write-Once Read-Multiple Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 20H V 21H V 22H V 23H V 24H V 25H E READ CAPACITY 8.2.1 26H V 27H V 28H M READ 12.2.1 29H V 2AH M WRITE 12.2.2 2BH O SEEK 8.2.4 2CH V 2DH V 2EH O WRITE AND VERIFY 12.2.3 2FH O VERIFY 12.2.4 30H O SEARCH DATA HIGH 8.2.7.1 31H O SEARCH DATA EQUAL 8.2.7.2 32H O SEARCH DATA LOW 8.2.7.3 33H O SET LIMITS 8.2.8 34H R 35H R 36H R 37H R 38H R 39H O COMPARE 7.2.1 3AH O COPY AND VERIFY 7.2.2 3BH R 3CH R 3DH R 3EH R 3FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 12.2.1 READ Command Periphera Devic Type Writ-Once Read-Multiple and Read-Onl Direc Access Operation Code Type: Mandatory Operation Code: 28H Table 12-9 READ Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th REA comman (Tabl 12-9 request tha th targe transfe dat t th initiator from the medium. Th logica bloc addres specifie th logica bloc a whic th rea operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat tha shal b transferred transfe lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a error An othe valu indicate th numbe o logica block tha shal b transferred. Thi comman shal b terminate wit statu o RESERVATIO CONFLIC i an reservatio acces conflic (se 8.1.8 exist an n dat shal b transferred. I an o th followin condition occur thi comman shal b terminate wit CHEC CONDITIO statu and i extende sens i implemented th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus th CHEC CONDITIO status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to read a blank or previously unwritten block BLANK CHECK (see note 2) NOTES: (1 Th extende sens informatio byte shal b se t th logica bloc addres o th firs invali address. (2 Th extende sens informatio byte shal b se t th logica bloc addres o th firs blan bloc encountered Th dat rea u t tha bloc shal b transferred 12.2.2 WRITE Command Peripheral Device Type: Write-Once Read-Multiple Operation Code Type: Mandatory Operation Code: 2AH Table 12-10 WRITE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT comman (Tabl 12-10 request tha th targe writ th dat transferre fro th initiato t th medium. Th logica bloc addres specifie th logica bloc a whic th writ operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat tha shal b transferred transfe lengt o zer indicate tha n dat shal b transferred Thi conditio shal no b considere a a erro an n dat shal b written An othe valu indicate th numbe o logica block tha shal b transferred. Thi comman shal b terminate wit statu o RESERVATIO CONFLIC i an reservatio acces conflic (se 8.1.8 exist an n dat shal b written. I an o th followin condition occur thi comman shal b terminate wit CHEC CONDITIO statu and i extende sens i implemented th sens ke shal b se a indicate i th followin table Thi tabl doe no provid a exhaustiv enumeratio o al condition tha ma caus th CHEC CONDITIO status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to write a previously written block and blank checking is enabled (see 12.1.3) BLANK CHECK (see note 2) NOTES: (1 Th extende sens informatio byte shal b se t th logica bloc addres o th firs invali address. (2 Th extende sens informatio byte shal b se t th logica bloc addres o th firs non-blan bloc encountered .pa 12.2.3 WRITE AND VERIFY Command Peripheral Device Type: Write-Once Read-Multiple Operation Code Type: Optional Operation Code: 2EH Table 12-11 WRITE AND VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BytChk | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th WRIT AN VERIF comman (Tabl 12-11 request tha th targe writ th dat transferre fro th initiato t th mediu an the verif tha th dat i correctl written. byt chec (BytChk bi o zer cause th verificatio t b simpl mediu verificatio (CRC ECC etc) BytCh bi o on cause byte-by- byt compar o dat writte t th periphera devic an th dat transferre fro th initiator I th compar i unsuccessfu, th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t MISCOMPARE. Th logica bloc addres specifie th logica bloc a whic th writ operatio shal begin. Th transfe lengt specifie th numbe o contiguou logica block o dat tha shal b transferred transfe lengt o zer indicate tha n logica block shal b transferred Thi conditio shal no b considere a a erro an n dat shal b written An othe valu indicate th numbe o logica block tha shal b transferred. .pa 12.2.4 VERIFY Command Periphera Devic Type Writ-Once Read-Multiple and Read-Onl Direc Access Operation Code Type: Optional Operation Code: 2FH Table 12-12 VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BlkVfy | BytChk | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Verification Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Verification Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== Th VERIF comman (Tabl 12-12 request tha th targe verif th dat o th medium. byt chec (BytChk bi o zer cause th verificatio t b simpl mediu verificatio (CRC ECC etc) BytCh bi o on cause byte-by- byt compar o th dat o th mediu an th dat transferre fro th initiator Th dat shal b transferre a i woul b fo WRIT command I th compar i unsuccessful th comman shal b terminate wit CHEC CONDITIO statu an th sens ke shal b se t MISCOMPARE. blan verif (BlkVfy bi o on cause verificatio tha th block ar blank. Th logica bloc addres specifie th logica bloc a whic th verif operatio shal begin. Th verificatio lengt specifie th numbe o contiguou logica block o dat o blank tha shal b verified verificatio lengt o zer indicate tha n logica block shal b verified Thi conditio shal no b considere a a error An othe valu indicate th numbe o logica block tha shal b verified. .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 13 # 13. Command Descriptions for Read-Only Direct-Access Devices 13. Grou Command fo Read-Onl Direct-Acces Devices. Th Grou command fo read-onl direct-acces device shal b a show i Tabl 13-1. Table 13-1 Group 0 Commands for Read-Only Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H O REZERO UNIT 8.1.1 02H V 03H M REQUEST SENSE 7.1.2 04H R 05H V 06H V 07H R 08H O READ 12.1.1 09H V 0AH R 0BH O SEEK 8.1.6 0CH V 0DH V 0EH V 0FH V 10H V 11H V 12H E INQUIRY 7.1.3 13H V 14H V 15H O MODE SELECT 12.1.3 16H O RESERVE 8.1.8 17H O RELEASE 8.1.9 18H O COPY 7.1.4 19H V 1AH O MODE SENSE 12.1.4 1BH O START/STOP UNIT 8.1.11 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH O PREVENT/ALLOW MEDIUM REMOVAL 8.1.12 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 13. Grou Command fo Read-Onl Direct-Acces Devices. Th Grou command fo read-onl direct-acces device shal b a show i Tabl 13-2. Table 13-2 Group 1 Commands for Read-Only Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 20H V 21H V 22H V 23H V 24H V 25H E READ CAPACITY 8.2.1 26H V 27H V 28H M READ 12.2.1 29H V 2AH R 2BH O SEEK 8.2.4 2CH V 2DH V 2EH R 2FH O VERIFY 12.2.4 30H O SEARCH DATA HIGH 8.2.7.1 31H O SEARCH DATA EQUAL 8.2.7.2 32H O SEARCH DATA LOW 8.2.7.3 33H O SET LIMITS 8.2.8 34H R 35H R 36H R 37H R 38H R 39H O COMPARE 7.2.1 3AH O COPY AND COMPARE 7.2.2 3BH R 3CH R 3DH R 3EH R 3FH R ============================================================================== Key: M = Command implementation is mandatory. E = Comman implementatio i require fo SCS device tha suppor device-independen self-configurin software. O = Command implementatio is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Section 14 # 14. Status  statu byt shal b sen fro th targe t th initiato durin th STATU phas a th terminatio o eac comman a specifie i Table 14- an 14- unles th comman i cleare b a ABOR message b BU DEVIC RESE message o b "hard RESE condition. Table 14-1 Status Byte  ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 |Reserved| Vendor Unique | Status Byte Code | V | ============================================================================== Table 14-2 Status Byte Code Bit Values ============================================================================== Bits of Status Byte ----------------------------- 7 6 5 4 3 2 1 0 Status(es) Represented ------------------------------------------------------------------------------ R V V 0 0 0 0 V GOOD R V V 0 0 0 1 V CHECK CONDITION R V V 0 0 1 0 V CONDITION MET/GOOD R V V 0 0 1 1 V Reserved R V V 0 1 0 0 V BUSY R V V 0 1 0 1 V Reserved R V V 0 1 1 0 V Reserved R V V 0 1 1 1 V Reserved R V V 1 0 0 0 V INTERMEDIATE/GOOD R V V 1 0 0 1 V Reserved R V V 1 0 1 0 V INTERMEDIATE/CONDITION MET/GOOD R V V 1 0 1 1 V Reserved R V V 1 1 0 0 V RESERVATION CONFLICT R V V 1 1 0 1 V Reserved R V V 1 1 1 0 V Reserved R V V 1 1 1 1 V Reserved ============================================================================== Key: R - Reserved bit V - Vendor unique bit .pa A description of the statu byt codes is given below: GOOD. Thi statu indicate tha th targe ha successfull complete th command. CHEC CONDITION. An error exception o abnorma conditio tha cause sens dat t b set shal caus CHEC CONDITIO status Th REQUES SENS comman shoul b issue followin CHEC CONDITIO status t determin th natur o th condition. CONDITIO MET. Th SEARC DAT command shal retur thi statu wheneve searc conditio i satisfied Thi statu doe no brea chai o linke commands Th logica bloc addres o th logica bloc tha satisfie th searc ma b determine wit REQUES SENS command. BUSY. Th targe i busy Thi statu shal b returne wheneve targe i unabl t accep comman fro a initiator Th norma initiato recover action is to issue the command again at a later time. INTERMEDIATE. Thi statu shal b returne fo ever comman i serie o linke command (excep th las command) unles a error exception o abnorma conditio cause CHEC CONDITIO statu o RESERVATIO CONFLIC statu t b set I thi statu i no returned th chai o linke command i broken n furthe command i th serie ar executed. RESERVATIO CONFLICT. Thi statu shal b returne wheneve a SCS devic attempt t acces logica uni o a exten withi logica uni tha i reserve fo tha typ o acces t anothe SCS device. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Appendix A # .pn 174 Appendixes (Thes Appendixe ar no par o America Nationa Standar Smal Compute Syste Interface X3.131.198_ bu ar include fo informatio only.) Appendix A SCSI Signal Sequence Example Thi appendi i include t provid a exampl o th timin o a SCS comman tha include mos o th SCS bu phase (Figur A1) I thi example th targe doe no disconnec fro th SCS bu prio t completin th command. The following notes apply to Figure A1: GENERAL NOTE: I typica system th computer' hos adapte act a th "initiator an th periphera device' controlle act a th "target" I general thi standar doe no attemp t distinguis betwee compute an it hos adapter Thes function ma b separat o merged Th ter "initiator encompasse both Similarly th ter "target doe no distinguis betwee th periphera devic an it controller whic ma b separat o merged Th ter "SCS device refer t devic tha ma b connecte t th SCS bus A SCS devic ma ac a i th initiato role th targe role o bot roles. TIMING NOTES: Bu Settl Delay. Th minimu tim t wai fo th SCS bu t settl afte changin certai contro signals. Bu Fre Delay. Th minimu tim tha a SCS devic mus wai fro it detectio o BU FRE phas unti i ma asser BS an it I bit. Bu Se Delay. Th maximu tim tha a SCS devic ma wai t asser BS an it I bi afte BU FRE phas wa las detecte i i intend t participat i th ARBITRATIO phase. Bu Clea Delay. Th maximu tim fo a SCS devic t sto drivin al signal afte BU FRE phas i detected afte SE i receive durin ARBITRATIO phase o afte RS become true. Arbitratio Delay. Th minimu tim tha a SCS devic mus wai afte assertin BS fo arbitratio unti i ma examin th DAT BU t determin whethe i won Ther i n maximu time. .pa .. Figure A1 goes here. .pa DATA BUS NOTES: (1) DB(7) is the most significant bit. (2) DB(7) is the highest priority arbitration bit. (3 DB(P i th dat parit bi (odd) Parit i no vali durin th ARBITRATIO phase Us o parit i syste optio (i.e. syste i configure s tha al SCS device o bu generat parit an hav parit detectio enabled o al SCS device hav parit detectio disable o no implemented). BUS PHASE NOTES: BU FRE phase. BU FRE phas begin whe SE an BS ar bot continuousl false for a bus settle delay. It ends when SEL or BSY becomes true. ARBITRATIO phase. Implementatio o thi phas i optional I ther i mor tha on initiator the al initiator mus implemen thi phase Target tha d no implemen thi phase canno disconnec fro th bu unti th comman ha completed SCS device tha implemen th COP comman mus implemen ARBITRATIO phase. A leas on bu fre dela afte firs detectin BUS FREE phase bu n mor tha bu se dela afte th bu wa las free th initiato assert BS an it assigne SCS devic I bi o th DAT BUS Th initiato wait a arbitratio delay the examine th DAT BUS I highe priorit SCS devic I bi i true th initiato lose arbitratio an release BS an it I bit Otherwise th initiato win arbitratio an assert SEL SCS device mus releas BS an thei I bi withi bu clea dela afte SE becomes true (even if they have not yet examined the DATA BUS). Th winnin SCS devic wait a leas bu clea dela plu bu settl delay after asserting SEL before changing any signals on the bus. SELECTIO phase. Th I/ signa i fals durin thi phas t distinguis i fro th RESELECTIO phase. NON-ARBITRATIN SYSTEMS I suc systems th initiato wait a leas bu clea dela afte detectin BU FRE phase the i assert th target' I bi and optionally th initiator' I bi o th DAT BUS Afte a leas tw deske delays th initiato assert SEL. ARBITRATIN SYSTEMS I suc systems th SCS devic tha wo arbitratio ha bot BS an SE asserted Afte a leas bu clea dela plu bu settl delay i place bot th target' an th initiator' I bit o th DAT BUS A leas tw tw deske delay later i release BSY. AL SYSTEMS Th targe determine tha i i selecte whe SE an it SCS I bi ar tru an BS an I/ ar fals fo a leas bu settl delay Th targe the assert BS withi selectio abor tim afte i las determine tha i wa stil bein selected (Th targe i no require t respon t selectio withi selectio abor time bu i mus insur tha i wil no asser BS mor tha selectio abor tim afte th initiato abort selectio attempt.) .fo Appendix A 176.1 A leas tw deske delay afte th initiato detect BS true i release SE an ma chang o releas th DAT BUS COMMAN phase. Th targe assert C/ an negate I/ an MS fo al o th byte transferre durin thi phase Th directio o transfe i fro th initiato t th target. HANDSHAK PROCEDURE Th targe assert REQ Upo detectin RE true th initiato drive th DAT BU t th desire value wait a leas on deske dela plu cabl ske dela an the assert ACK Th initiato continue to drive the DATA BUS until REQ is false. Whe AC i tru a th target th targe read th DAT BU an the negates REQ. Whe RE become fals a th initiator th initiato ma chang o releas the DATA BUS and negate ACK. Th targe ma continu t reques comman byte b assertin RE again Th numbe o comman byte i determine b th grou cod (mos significan bits tha i containe i th firs comman byte. DAT I phase. Th targe assert I/ an negate C/ an MS fo al o th byte transferre durin thi phase Th directio o transfe i fro th target to the initiator. HANDSHAK PROCEDURE Th targe firs drive th DAT BU t thei desire values wait a leas on deske dela plu cabl ske delay an the asserts REQ. The target continues to drive the DATA BUS until ACK is true. Whe RE i tru a th initiator th initiato read th DAT BU an the asserts ACK. Whe AC i tru a th target th targe ma chang o releas th DAT BUS and negate REQ. Whe RE i fals a th initiator th initiato negate ACK Afte AC i false th targe ma continu th transfe b drivin th DAT BU an asserting REQ as described above. DAT OU phas (no show i th figure). Th targe negate C/D I/O an MS fo al o th byte transferre durin thi phase Th directio o transfe i fro th initiato t th target (Refe t th handshak procedure and the timing chart for the COMMAND phase.) STATU phase. Th targe assert C/ an I/ an negate MS fo th byt transferre durin thi phase Th directio o transfe i fro th targe t th initiator (Refe t th handshak procedur an th timin char fo th DATA IN phase.) MESSAG phase. Th targe C/D I/O an MS durin th byt transferre durin thi phase Typically COMMAN COMPLET messag woul b sen a thi point Th directio o transfe i fro th targe t th initiator (Refe t th handshak procedur an th timin char fo th DAT I phase.) BU FRE phase. Th targe return t BU FRE phas b releasin BSY Bot th targe an th initiato releas al bu signal withi bu clea dela after BSY is continuously false for a bus settle delay. .fo Appendix A 176.2 .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .pn 177 .fo Appendix B # Appendix B Typical Bus Phase Sequence Thi appendi i include t provid a exampl o th SCS bu phas sequenc fo typica REA comman (Table B an B2) I thi example th targe doe no disconnec fro th SCS bu prio t completin th command. Table B1 Typical READ Command Phase Sequence ============================================================================== Signals --------------------------------------------------------------- B S A M C I R A R D D S E T S / / E C S B B Bus Phase Y L N G D O Q K T (7-0) (P) Comment ------------------------------------------------------------------------------ BU FRE - - - - - - - - - - - SCS bu i available. ARBITRATIO - - - - - - - - I Initiato trie t get th SCS bus. SELECTIO - - - - - I I, Initiato ha SCS bus - I I, an select target. I I, ATN is on. - MESSAG OU - - Target ha controo the bus an get the IDENTIF messag fro Messag the initiator. COMMAN - - Target get a comman fro the initiator Comman (Thi phas i repeate fo eac byte.) ============================================================================== .pa Table B2 Typical READ Command Phase Sequence (Continued) ============================================================================== Signals --------------------------------------------------------------- B S A M C I R A R D D S E T S / / E C S B B Bus Phase Y L N G D O Q K T (7-0) (P) Comment ------------------------------------------------------------------------------ DAT I - - Targe send dat to Rea Dat the initiator (Thi phase i repeate fo each byte. STATU - - Targe send statu to Statu the initiator X MESSAG I - - Targe send a COMMAND Messag COMPLET messag to the initiator BU FRE - - - - - - - - - - - SCS bu i available. ============================================================================== Key: - = Signaldriver is passive. 0 = Signal is false. 1 = Signal is true. "Blank" = Signal state is the same as the previous line. ID = SCSI ID for arbitration. ID I,T = SCSI ID of initiator and target. V = Parity is valid. X = The signal is not guaranteed to be in a known state. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .pn 179 .fo Appendix C # Appendix C SCSI System Operation Thi appendi i include t provid a explanatio o th relationshi o th variou piece o a SCS system Thi appendi als provide additiona informatio abou th us o SCS i multi-taskin system Suc system typicall us hos adapte printed-circui boar t interfac fro th hos memor t th SCS bus Althoug othe architecture ar possibl (includin nativ o imbedde SCSI) th hos adapte logi stil exist a par o th system Th ter "initiator i use throughou thi standar t encompas al suc architectures Th ter "hos adapter i use withi thi appendi t refe t th logi tha interface fro th hos memor t th SCS bus. C1. Host Memory / Host Adapter / SCSI Controller Relationship Th SCS architectur utilize th concep o hos memor block fo command data an statu interchang betwee th hos syste an th SCS controller I th middl o thi exchang i th SCS hos adapter whic act a th SCS peripheral' gatewa int hos memory Th hos adapte i a importan portio o th overal intelligenc o SCSI Alon wit providin a informatio pat fro th SCS bu t th hos bus th hos adapte i intimatel involve i assurin dat integrit an prope performanc o th I/ subsystem I orde t full understan SCS operation th concept o I/ memor block an logica thread mus b detailed Figur C present bloc diagra o singl host/singl periphera SCS I/ subsystem Th hos memor contain thre I/ blocks command data an status Th SCS controlle need t rea th comman bloc an writ t th statu bloc i orde t perfor th tas specifie b th hos (i th comman block) Likewise th controlle need t bot rea an writ th dat block A wa previousl mentioned th SCS controlle "reache int hos memory vi th SCS hos adapter Th hos adapte mus kno th addresse o th command data an statu block i orde fo i t "reach int th righ spo i memory I othe words th hos adapte mus b give pointe t th star o eac bloc b th host A th SCS controlle take informatio fro th comman block th memor pointe fo th comman bloc advancs t th nex byte Th sam i tru fo th dat an statu pointers. SCS architectur provide fo tw set o thre pointer withi th hos adapter Th firs se i know a th curren (o active pointe values Thes ar th pointer t th nex command data o statu byt t b transferre betwee th hos memor an th SCS controller Ther i onl on se o curren pointer i th hos adapter Th curren pointer ar share amoun al device an ar use b th curren devic connecte t th hos adapter Th secon se i know a th save pointe values Ther i on se o save pointer fo eac supporte logica thread Fo comman an status thes pointer alway poin t th star o th memor comman bloc an memor statu block Th save dat pointe point t th star o th dat bloc a th beginnin o th SCS command I remain a thi valu unti th controlle send SAV DAT POINTE messag t th hos adapte whic i tur save th valu o th curren dat pointer Th controlle ma retriev th save valu b sendin RESTOR POINTER message Thi move th save valu o eac pointe int th curren pointe registers Wheneve a SCS devic disconnect fro th bus onl th save pointe value ar retained Th curren pointe value ar se fro th save value upo th nex reconnection Th curren an save pointer provid a efficien mean o erro retr an recover durin larg dat exchange o th SCS bus. C2. SCSI READ Command Example On metho t understandin th host/hos adapter/SCS periphera relationshi i vi a example Le u conside th cas o multipl secto REA comman tha wil cros cylinde boundar o direct-acces devic suc a disk Th firs activit i th I/ operatio i fo th syste t creat comman descripto bloc i memor an determin wher th dat an statu ar t b writte i hos memory Th hos the send comman t th hos adapte tha include th startin addres (pointer fo eac o th command data an statu block an th SCS addres o th periphera t perfor th operation I thi example ther i onl on SCS controlle an physica disk bu it addres i require i orde fo th hos adapte t selec it. Upo receivin th command th hos adapte arbitrate fo th SCS bu an win (du t th lac o competin devices an proceed t selec th targe SCS devic wit th AT signa asserted Th ATTENTIO conditio indicate t th SCS targe tha th initiato (th hos adapter ha messag t sen t th target. Afte th SELECTIO phas i completed th dis controlle respond t th initiator' ATTENTIO conditio b receivin messag fro th initiator Thi message generate b th hos adapter indicate th desire logica uni numbe i th targe an whethe th initiato ca suppor bu disconnect I thi example th initiato support disconnect. Input/outpu activit fro thi poin wil b controlle entirel b th target Th hos adapte i simpl a "arm o th targe use t reac int hos memory Utilizin thi arm th targe read i th comman descripto bloc (CDB). Afte decodin th instruction th controlle determine tha dis see i require t ge th startin dat block Sinc th SCS bu wil no b utilize unti dat ha bee rea fro th disk th targe controlle disconnect fro th bus Th disconnec proces include th transmissio o SAV DAT POINTE messag an DISCONNEC messag fro th targe t th hos adapter Th hos adapte respond t th SAV DAT POINTE messag b savin th curren dat pointer whic i stil se t th star o th dat block Afte transmissio o th DISCONNEC messag th targe wil releas BSY freein th bus. Althoug th initiato hos adapte an targe dis controlle ar disconnected the ar logicall connecte or "threaded" together Bot device kno the hav comman t finis an wil retur t tha jo a late poin i time Th principl o logica thread allow man I/ command t execut i th syste simultaneously utilizin singl physica bus Th threa i actuall no betwee th hos adapte an th dis controller bu run al th wa fro th hos memor I/ bloc t th periphera devic performin th operation (Se Figur C fo pictoria presentatio o thi concept.) Onc th targe ha starte fillin it dat buffers i ca transmi dat t th initiator bu firs i mus reestablis th physica path Th reselectio proces involve th targe arbitratin fo th bu an reselectin th hos adapter Afte th physica reconnectio i made th targe send a IDENTIF messag t th hos adapte t indicat whic targe logica uni i reconnecting Thi informatio provide reconnection t th correc threa int hos memory Afte reconnection th role o th initiato an targe ar jus a the wer prio t disconnect Th targe transfer dat int hos memor vi th hos adapter Th dat transfe continue unti th dis reache th en o it cylinde an th dis controlle determine tha secon physica see i require t complet th REA command Th targe agai perform SAV DAT POINTE messag an DISCONNEC message However thi tim th curren dat pointe i no a th beginnin o th memor dat block Th save valu a disconnec reflect th change. Afte see completio an transfe o dat int it buffer th controlle reconnect t th hos adapte an complete th dat transfe a requeste b th REA command A thi point th controlle send endin statu int hos memor vi th hos adapter Th fina actio o th targe i t sen t th hos adapte COMMAN COMPLET messag an disconnec fro th SCS bus Th targe ha complete it operatio an consider th logica threa broken. Upo receip o th COMMAN COMPLET message th hos adapte signal th hos tha th I/ comman i complete Thi signa ca b a interrup o th settin o fla rea b th hos i polle I/ environment Thi actio b th hos adapte break th threa betwee th hos adapte an th I/ memor block o th host Th hos review th statu o th operatio i th statu bloc an proceed t utiliz th dat transferre int th dat block. C3. I/O Channel Concept Th I/ channe concep full utilize th hig performanc capabilit o SCSI Th I/ channe i basicall a intelligen SCS hos adapte tha ca maintai multipl simultaneou thread betwee hos memor I/ block an differen SCS devices Th I/ channe utilize singl direc memor acces (DMA pat int hos memor supportin th DM operation o numerou SCS peripherals Sinc th SCS bu i singl physica bu an mos hos computer hav singl physica backplan bus multipl DM channel int memor ar no necessary I man implementation o multipl DM channe architecture whe channe i accessin memory al othe channel ar idle I suc implementations singl channe supportin multipl thread ca suppl th sam performanc a separat DM peripherals A obviou advantag t th hos i lowe syste cos a wel a th savin i backplan car slots. I th REA comman exampl discusse i Sectio C2 th I/ channe i th SCS hos adapter Th hos give th I/ channe comman b providin i wit pointer t th I/ memor block an th SCS periphera address Thi establishe threa betwee th hos adapte an th hos I/ memor blocks Th I/ channe the open subchanne tha i assigne th tas o managin th physica lin an logica threa betwee th hos adapte an th targe controller Al physica connection an reconnection t th hos adapte ar manage b thi subchannel Th numbe o activ o ope subchannel a I/ channe ca suppor i totall dependen upo it design Th SCS definitio could i theory suppor a I/ channe wit u t 5 subchannel (14,33 subchannels i th EXTENDE IDENTIF messag i implemented). Figure C1. Snapshot Prior to Initial Selection Figure C2. Snapshot Prior to Data Transfer .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .pn 184 .fo Appendix D # Appendix D  Recommended Shielded Connectors Thre alternativ shielde connecto system ar define b thi appendix Fo eac alternative th connecto shieldin syste shal provid d resistanc o les tha 10milliohm fro th cabl shiel a it terminatio poin t th SCS devic enclosure. I orde t suppor daisy-chai connections SCS device tha us shielde connector shoul provid tw shielde devic connector o th devic enclosure Thes tw connector ma b wire "one-to-one wit stu t th SCS device' driver an receiver provide th maximu stu lengt i no violated Alternatively tw cable ma b ru fro th tw shielde connector t th driver an receiver s tha th maximu stu lengt i no violated Th lengt o th cabl withi th devic enclosur i include whe calculatin th tota cabl lengt o th SCS bus. D Shielde Connector Alternativ 1. Th shielde cabl connecto (Figur D1 shal b 50-conducto connecto consistin o tw row o 2 femal contact wit adjacen contact 2.5 m (0. in apart Th nonmatin portio o th connecto i show fo referenc only. Th shielde SCS devic connecto (Figur D2 shal b 50-conducto connecto consistin o tw row o 2 mal pin wit adjacen pin 2.5 m (0. in apart Th nonmatin portio o th connecto i show fo referenc only. Th connecto pi assignment shal b a show i Tabl 4- fo single- ende driver an a show i Tabl 4- fo differentia drivers. D Shielde Connector Alternativ 2. Th shielde devic connecto (Figur D3 shal b 50-conducto connecto consistin o tw row o ribbo contact space 2.1 m (0.08 in apart Th nonmatin portio o th connecto i show fo referenc only FC documen Par 6 Subpar 68.50 shoul b use fo reference. Th shielde cabl connecto (Figur D4 shal b 50-conducto connecto consistin o tw row o ribbo contact space 2.1 m (0.08 in apart Th nonmatin portio o th connecto i show fo referenc only. Th connecto pi assignment shal b a show i Tabl D fo single-ende driver an a show i Tabl D fo differentia drivers. D EUROCAR Boxes Fo board i EUROCAR boxe (IE 29 o DI 41494 th EMI-scree ma b i th fron o th board an i thi cas screene cabl an connecto ma b attache throug th fron pane t th boar connecto specifie i sectio 4.3 I i thereb possibl t us th fla ribbo cabl specifie i thi standar o th shielde cable a require b users. .pa Figure D1a. Female Shielded SCSI Cable Connector, Alternative 1 .pa ============================================================================== Dimensions Millimeters Inches ------------------------------------------------------------------------------ A1 60.96 + 0.15 2.400 + 0.006 A2 66.29 + 0.18 2.610 + 0.007 A3 2.54 + 0.15 0.100 + 0.006 A4 2.54 + 0.15 0.100 + 0.006 A5 8.56 + 0.41 0.337 + 0.016 A6 11.93 Minimum 0.470 Minimum A7 65.02 + 0.18 2.560 + 0.007 A8 5.46 0.215 A9 4.14 + 0.25 0.163 + 0.010 A10 60.20 Maximum 2.370 Maximum A11 6.60 0.260 A12 1.27 Maximum 0.050 Maximum A13 0.64 Maximum 0.025 Maximum A14 6.604 + 0.25, - 0.13 0.260 + 0.010, - 0.005 A15 13.46 0.530 A16 12.45 + 0.38 0.490 + 0.015 ============================================================================== NOTES: (1 Fift Contact o 2.54-m (0.100-inch spacin 60.9 m (2.4 inch). (2 Tolerance +_ 0.12 m (0.00 inch noncumulative unles specifie otherwise. Figure D1b. Female Shielded SCSI Cable Connector, Alternative 1 .pa Figure D2a. Male Shielded SCSI Device Connector, Alternative 1 .pa ============================================================================== Dimensions Millimeters Inches ------------------------------------------------------------------------------ B1 66.65 + 0.15 2.624 + 0.006 B2 65.28 2.570 B3 0.69 0.027 B4 5.77 + 0.81 0.227 + 0.032 B5 9.14 0.360 B6 3.30 0.130 B7 2.54 0.100 B8 2.54 0.100 B9* 2.84 0.112 B10 0.15 0.006 B11 0.38 0.015 B12 8.15 + 0.76, - 0.48 0.321 + 0.030, - 0.019 B13 0.64 + 0.02 0.025 + 0.001 B14* 0.64 Square 0.025 Square B15 78.84 3.104 B16* 5.77 0.227 B17* 2.92 0.115 B18 4.83 0.190 B19* 3.18 0.125 B20* 1.52 0.060 B21 67.31 2.650 B22 9.65 0.380 ============================================================================== NOTES: (1) Fifty Contacts on 2.54-mm (0.100-inch) spacing = 60.96 mm (2.40 inch). (2 Tolerance + 0.12 m (0.00 inch noncumulative unles specifie otherwise. (3) Dimensions listed with asterisks (*) are shown for reference only. Figure D2b. Male Shielded SCSI Device Connector, Alternative 1 .pa Figure D3. Shielded SCSI Device Connector, Alternative 2 .pa Figure D4. Shielded SCSI Cable Connector, Alternative 2 .pa Table D1 Single-Ended Pin Assignments (Shielded Connector, Alternative 2) ============================================================================== Signal Pin Number ------------------------------------------------------------------------------ -DB(0) 26 -DB(1) 27 -DB(2) 28 -DB(3) 29 -DB(4) 30 -DB(5) 31 -DB(6) 32 -DB(7) 33 -DB(P) 34 GROUND 35 GROUND 36 GROUND 37 TERMPWR 38 GROUND 39 GROUND 40 -ATN 41 GROUND 42 -BSY 43 -ACK 44 -RST 45 -MSG 46 -SEL 47 -C/D 48 -REQ 49 -I/O 50 ============================================================================== NOTES: (1 Pin 1_1 an 14_25 shal b connecte t ground Pi 1 shoul b lef open Som product designe prio t th generatio o thi standar connecte thi pi t ground. (2 Th minu sig nex t th signal indicate activ low. .pa Table D2 Differential Pin Assignments (Shielded Connector, Alternative 2) ============================================================================== Signal Name Pin Number Signal Name ------------------------------------------------------------------------------ SHIELD GROUND 1 26 GROUND +DB(0) 2 27 -DB(0) +DB(1) 3 28 -DB(1) +DB(2) 4 29 -DB(2) +DB(3 5 30 -DB(3) +DB(4) 6 31 -DB(4) +DB(5) 7 32 -DB(5) +DB(6) 8 33 -DB(6) +DB(7) 9 34 -DB(7) +DB(P) 10 35 -DB(P) DIFFSENS 11 36 GROUND GROUND 12 37 GROUND TERMPWR 13 38 TERMPWR GROUND 14 39 GROUND +ATN 15 40 -ATN GROUND 16 41 GROUND +BSY 17 42 -BSY +ACK 18 43 -ACK +RST 19 44 -RST +MSG 20 45 -MSG +SEL 21 46 -SEL +C/D 22 47 -C/D +REQ 23 48 -REQ +I/O 24 49 -I/O GROUND 25 50 GROUND ============================================================================== NOTE: (1 SHIEL GROUN i optiona o som cables (Implementor note Som shielded flat ribbon cables use pin 1 as a connection to the shield.) .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Appendix E # Appendix E Conformance Thi appendi contain recommendation o conformanc statement t thi standard. E1. Alternatives Thi standar contain variou alternative tha ar mutuall exclusiv withi a system. (1) Single-ended or differential drivers. (2) Termination power supplied by the cable or not. (3) Parity implemented or not. (4) "Hard" RESET or "soft" RESET. (5) Reservation queuing implemented or not. E2. Levels of Conformance B specifyin whic alternative (liste above ar implemented a environmen i create enablin differen feature t b implemented Thes feature ar divide int thre neste minimu level a show i Tabl E1. Table E1 Levels of Conformance ============================================================================== Level Initiator Target ------------------------------------------------------------------------------ 0 Accept COMMAND COMPLETE Implement the mandatory commands message. of section 7. Accept GOOD and CHECK Implement the mandatory commands CONDITION status codes. of the supported device type(s). Implement the COMMAND COMPLETE message. If messages other than COMMAND COMPLETE are implemented, then implement MESSAGE REJECT message also. Implement GOOD and CHECK CONDITION statuses. ------------------------------------------------------------------------------ 1 Same as above plus Same as above. ARBITRATION phase. ------------------------------------------------------------------------------ 2 Same as above plus Same as above plus implement the accept DISCONNECT, MESSAGE REJECT and IDENTIFY messages MESSAGE REJECT, and implement all extended commands IDENTIFY, and SAVE in section 7 and for the supported DATA POINTER messages device type(s). ============================================================================== E3. Options E3. Optiona Commands. Thi standar specifie numbe o additiona command tha ca b implemente i eac level Som o thes commands i implemented requir th implementatio o othe optiona commands messages o both I thi case thes additiona commands messages o bot shal als b implemented. E3. Optiona Messages. Thi standar specifie numbe o additiona optiona message tha ma b implemente a an level. E3. Othe options. Withi som commands additiona feature, calle "options" ar described Thes option nee no necessaril b implemented. E4. Statement of Conformance An statemen o conformanc t thi standar shoul declar whic o th alternate liste i sectio E an whic o th thre conformanc level ar implemented I addition i shoul indicat whic o th option liste i sectio E ar implemented i any I th cas o optiona messages th conformanc statemen shoul stat whethe th messag i generated accepted or both. I th synchronou dat transfe optio i implemented an statemen o conformanc shoul s indicat an stat bot th maximu REQ/AC offse an the minimum transfer period implemented. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .pn 195 .fo Appendix F # Appendix F Additional Medium Type and Density Code Standards I section an o thi standard th MOD SELEC an MOD SENS command defin mediu typ code an densit code fo certai flexibl disk an magneti tapes ANS standard o X draf document ar reference fo cod value i standar o draf documen exist fo tha cod value I man cases othe standard als exis fo cod value Table F an F i thi appendi provide reference t thos standard fo thes cod values. DISCLAIMER I i no th purpos o thi appendi t indicat tha thes standard ar exactl equivalen t eac other However thes standard ma b applicable Pleas refe t section an fo additiona informatio concerning the medium type or density code. Table F1 Direct-access Medium Type Codes ============================================================================== Code Value Medium Type ---------- ------------------------------------------------------------------ 00H-02H See section 8. Flexible Disk Reference Standard(s) ------------------------------------------------------------------ 05H X3.73-1980, ECMA-54, ISO 5654/1-1984, ISO 5654/2-1982 06H X3B8-140, ECMA-59 09H X3B8/78-139 0AH X3.121-1984, ECMA-69, ISO 7065/1-1985, ISO 7065/2-1985 0DH X3.82-1980, ECMA-66, ISO 6596/1-1985, ISO 6596/2-1985 12H X3.125-1984, ECMA-70, ISO 7487/1-1985, ISO 7487/2-1985, ISO 7487/3-1985 16H X3.126-198X, ECMA-78, DIS 8378/1, DIS 8378/2, DIS 8378/3 1AH X3B8/85-199, ECMA-99, DIS 8630/1, DIS 8630/2 1EH X3.137-198X, ECMA-100, DIS 8860/1, DIS 8860/2 Direct-access Magnetic Tape Standard(s) ------------------------------------------------------------------ 40H X3B5/85-138 (Note 1), ECMA TC19/83/39 44H X3B5/85-138 (Note 1), ECMA TC19/83/39 80H _ FFH Vendor unique All others Reserved ============================================================================== NOTE: (1 Th reference standar i fo unrecorde miniatur cartridg media Th usag referre t her i fo seria GC recordin usin forma know a QIC-100 Sinc X3B issue ne documen numbe fo eac revisio o thei workin draf document pleas contac th Chairma o X3B fo th lates documen number. .pa Table F2 Sequential-access Density Codes ============================================================================== Code Value Density ---------- ------------------------------------------------------------------ 00H See section 9. Magnetic Tape Reference Standard(s) ------------------------------------------------------------------ 01H X3.22-1983, ECMA-62 02H X3.39-1973 ECMA-62 03H X3.54-1976, ECMA-62 04H Old format known as QIC-11 05H X3.136-198X, ECMA-98 06H X3B5/85-98 (Note 1) 07H X3.116-198X, ECMA-79 08H X3B5/85-77 (Note 1) 09H X3B5/85-76 (Note 1) 0AH 0BH X3.55, X3.56-198X, ECMA-46, ISO 4057-1979 80H _ FFH Vendor unique All others Reserved ============================================================================== NOTES: (1 Workin Draft X3B assign ne documen numbe t eac revisio o thei documents Pleas contac th Chairma o X3B fo th lates documen number. .pa .. To set ruler line, position cursor on the next line and type ^OF --!--!--!--!--!--!--!--!--!--!--!--!-----------------------------------------! .fo Appendix G # Appendix G Future Standardization Thi appendi i include t provid insigh int som possibl futur extension t SCS tha ar bein considere b X3T9.2 Althoug X3T9. ha addresse som o thes extensions man detail remai t b resolved Furthe wor b X3T9. ma resul i change o addition t thes extensions. Pleas contac th Chairma o X3T9. fo th curren statu o thi activity. Si ne command ar bein considered thre fo target tha suppor caching on t provid mean t rea th mediu defec data an tw t provid standardize metho fo writin an readin th target' dat buffe (principall intende t suppor start-of-da test tha insur dat pat integrity) Th tentativ operatio code ar a follows: ============================================================================== Operation Code Type Command Name Device Types ------------------------------------------------------------------------------ 34H O PRE-FETCH \ Direct Access, Write-Once 35H O FLUSH CACHE > Read-Multiple, and 36H O LOCK/UNLOCK CACHE / Read-Only Direct Access 37H O READ DEFECT DATA Direct Access 3BH O WRITE BUFFER All 3CH O READ BUFFER All ------------------------------------------------------------------------------ Ne parameter ar bein considere i severa o th existin commands: (1 Cach contro bit ar bein considere fo bit an o byt i severa grou commands includin READ WRITE WRIT AN VERIFY an VERIFY. (2 Byt o th Defec Lis i th FORMA UNI comman ma b use t provid additiona defec managemen control. (3 Bit _ o byt o th Inquir Dat i th INQUIR comman ma b use t identif tha th devic support certai addition t th standard On suc additio tha i bein considere i optiona field withi th Inquiry Data to identify the manufacturer and the product model information. (4 Extension t th MOD SELEC an MOD SENS command ar bein considere t provid standar mean t contro certai targe parameters Bit _ o byt o th MOD SENS comman ar bein considere fo us i controllin whic targe parameter ar returne b thi command. .pa