

NOTE: Following is the updated spec as of 10/16/89.  The spec version in
      the new C2x User's Guide (SPRU014A) is the spec as of 5/15/89.
      The updates to the 5/15 spec are as follows:

      parm	5/15 spec     10/16 spec
  --------------------------------------
  td(SL-R)max    Q-21           Q-20
  td(C2H-R)max   Q-21           Q-20
  tsu(D)Rmin     19             17
  tw(SH)min      2Q             2Q-2
  ta(A) 	 3Q-30		3Q-31


				 TMS320C25-50

		     PRELIMINARY ELECTRICAL SPECIFICATION

				   10/16/89






























  * See	"NOTES"	section	when suggested in document, following TMS320C25-50
    data, for additional information concerning	parameters.






*** Texas Instruments (TI) reserves the	right to make changes to this document
    without notice.


			       TMS320C25-50


ABSOLUTE MAXIMUM RATINGS OVER SPECIFIED	TEMPERATURE RANGE (Unless noted)*

       Supply voltage range, VCC** ................... -0.3V to	7V
       Input voltage range ........................... -0.3V to	7V
       Output voltage range .......................... -0.3V to	7V
       Continuous power	dissipation .................. 1.5W
       Operating free-air temperature range .......... 0C to 70C
       Storage temperature range ..................... -55C to 150C

 * Stresses beyond those listed	in this	section	may cause permanent damage to
   device. Exposure to these conditions	for extended periods may affect	device
   reliability.	 This is a stress rating only and functional operation,	of the
   device or any conditions beyond those listed	in the RECOMMENDED OPERATING
   CONDITIONS section, is not implied.

** All voltage values are with respect to VSS.



RECOMMENDED OPERATING CONDITIONS
==============================================================================
	     PARAMETER			       | MIN	 NOM	 MAX	|UNIT
===============================================|========================|=====
VCC Supply Voltage			       | 4.75	  5	 5.25	|  V
-----------------------------------------------|------------------------|-----
VSS Supply Voltage			       |	  0		|  V
-----------------------------------------------|------------------------|-----
			    |INT(0-2)-	       | 2.5			|  V
			    |------------------|------------------------|-----
VIH High-level input voltage|CLKIN,CLKX,CLKR   | 3.5			|  V
			    |------------------|------------------------|-----
			    |Other inputs      | 2.35			|  V
----------------------------|------------------|------------------------|-----
                            |MPMC-             |                  0.8   |  V
			    |------------------|------------------------|-----
VIL Low-level input voltage |CLKIN	       |		  0.8	|  V
			    |------------------|------------------------|-----
			    |Other inputs      |		  0.8	|  V
-----------------------------------------------|------------------------|-----
IOH High-level output current		       |		  300	| uA
-----------------------------------------------|------------------------|-----
IOL Low-level output current		       |		    2	| mA
-----------------------------------------------|------------------------|-----
TA  Operating free-air temperature	       |  0		   70	|  C
==============================================================================

ELECTRICAL CHARACTERISTICS OVER	SPECIFIED FREE-AIR TEMP	RANGE (Unless noted)
==============================================================================
	 PARAMETER	      |	 TEST CONDITIONS   | MIN    TYP*   MAX | UNIT
==============================|====================|===================|======
VOH High-level output voltage |VCC=MIN,IOH=MAX	   | 2.4	       |  V
------------------------------|--------------------|-------------------|------
VOL Low-level output voltage  |VCC=MIN,IOL=MAX	   |		   0.6 |  V
------------------------------|--------------------|-------------------|------
IZ  Three-state	current	      |VCC=MAX		   | -20	    20 | uA
------------------------------|--------------------|-------------------|------
II  Input current	      |VI=VSS to VCC	   | -10	    10 | uA
------------------------------|--------------------|-------------------|------
                  | Normal    |                    |        110    185 |
ICC Supply current|-----------|TA=0C,VCC=MAX,fx=MAX|-------------------| mA
                  | Idle,Hold-|                    |         50    100 |
------------------------------|--------------------|-------------------|------
CI  Input capacitance	      |			   |	    15	       | pF
------------------------------|--------------------|-------------------|------
CO  Output capacitance	      |			   |	    15	       | pF
==============================================================================

* All typical values are at VCC=5V, TA=25C



			 CLOCK CHARACTERISTICS AND TIMING

The TMS320C25-50 can use either	its internal oscillator	or an external
frequency source for a clock.

INTERNAL CLOCK OPTION

The internal oscillator	in enabled by connecting a crystal across X1 and X2,
CLKIN. The frequncy of CLKOUT1 is one-forth the	crystal	fundamental frequency.
The crystal should be either fundamental or overtone mode, and parallel
resonant, with an effective series resistance of 30 ohms, a power dissipation
of 1 mW, and be	specified at a load capacitance	of 20 pF. Note that overtone
crystals require an additional tuned LC	circuit.

==============================================================================
	    PARAMETER	      |	  TEST CONDITIONS  | MIN   TYP	  MAX  | UNIT
==============================|====================|===================|======
fx     Input clock frequency  |	TA=0C to 70C	   | 6.7	  51.2 | MHz
------------------------------|--------------------|-------------------|------
fsx    Serial port frequency  |	TA=0C to 70C	   |  0		   6.4 | MHz
------------------------------|--------------------|-------------------|------
C1,C2			      |	TA=0C to 70C	   |	    10	       | pF
==============================================================================


EXTERNAL CLOCK OPTION

An external frequency source can be used by injecting the frequency directly
into X2,CLKIN with X1 left unconnected.	The external frequency injected	must
conform	to specifications listed in the	following table.


SWITCHING CHARACTERISTICS OVER RECOMMENDED OPERATING CONDITIONS	(See Note 1)
==============================================================================
			   PARAMETER			  ! MIN	 TYP  MAX|UNIT
==========================================================|==============|=====
tc(C)	   CLKOUT1,CLKOUT2 cycle time			  | 78.13     597! ns
----------------------------------------------------------|--------------|-----
td(CIH-C)  CLKIN high to CLKOUT1,CLKOUT2,STRB- high,low	  ! 12	       27! ns
----------------------------------------------------------|--------------|-----
tf(C)	   CLKOUT1,CLKOUT2,STRB- fall time		  !		3! ns
----------------------------------------------------------|--------------!-----
tr(C)	   CLKOUT1,CLKOUT2,STRB- rise time		  !		3! ns
----------------------------------------------------------!--------------|-----
tw(CL)	   CLKOUT1,CLKOUT2 low pulse duration		  ! 2Q-7       2Q! ns
--------------------------------------------------------- |--------------|-----
tw(CH)	   CLKOUT1,CLKOUT2 high	pulse duration		  ! 2Q	     2Q+3! ns
----------------------------------------------------------|--------------|-----
td(C1-C2)  CLKOUT1 high to CLKOUT2 low, 		  ! Q-6      Q+2 ! ns
	   CLKOUT2 high	to CLKOUT1 high,etc		  |		 |
===============================================================================



TIMING REQUIREMENTS OVER RECOMMENDED OPERATING CONDITIONS (See Note 1)
===============================================================================
		      PARAMETER				  | MIN	 NOM  MAX|UNIT
==========================================================|==============|=====
tc(CI)	 CLKIN cycle time				  |19.54      150| ns
----------------------------------------------------------|--------------|-----
tf(CI)	 CLKIN fall time				  |		5| ns
----------------------------------------------------------|--------------|-----
tr(CI)	 CLKIN rise time				  |		5| ns
----------------------------------------------------------|--------------|-----
tw(CIL)  CLKIN low pulse duration,tc(CI)=50ns (Note 2)    | 20           | ns
----------------------------------------------------------|--------------|-----
tw(CIH)  CLKIN high pulse duration,tc(CI)=50ns (Note 2)   | 20           | ns
----------------------------------------------------------|--------------|-----
tsu(S)	 SYNC- setup time before CLKIN low		  ! 4	      Q-4! ns
----------------------------------------------------------|--------------|-----
th(S)	 SYNC- hold time form CLKIN low			  ! 4		 ! ns
===============================================================================


		     MEMORY AND	PERIPHERAL INTERFACE TIMING

SWITCHING CHARACTERISTICS OVER RECOMMENDED OPERATING CONDITIONS	(See Note 1)
===============================================================================
		      PARAMETER				  ! MIN	 TYP  MAX|UNIT
==========================================================|==============|=====
td(C1-S) STRB- from CLKOUT1(if STRB- is present)	  | Q-5       Q+3| ns
----------------------------------------------------------|--------------|-----
td(C2-S) CLKOUT2 to STRB-(if STRB- is present)		  | -2		5| ns
----------------------------------------------------------!--------------!-----
tsu(A)	 Address setup time before STRB- low (Note 3)	  | Q-11	 ! ns
----------------------------------------------------------|--------------|-----
th(A)	 Address hold time after STRB- high  (Note 3)	  | Q-4		 ! ns
----------------------------------------------------------|--------------|-----
tw(SL)	 STRB- low pulse duration (no wait states, Note	4)! 2Q-5       2Q| ns
----------------------------------------------------------!--------------!-----
tw(SH)   STRB- high pulse duration (between consecutive   ! 2Q-2     2Q+3| ns
	 (cycles, Note 4)				  |		 |
----------------------------------------------------------|--------------!-----
tsu(D)W	 Data write setup time before STRB- high (no wait)! 2Q-17	 | ns
----------------------------------------------------------|--------------!-----
th(D)W	 Data write hold time from STRB- high		  ! Q-5 	 | ns
----------------------------------------------------------|--------------|-----
ten(D) Data bus	starts being driven after STRB-	low(write)| 0		 | ns
----------------------------------------------------------|--------------|-----
tdis(D)	 Data bus three-state after STRB- high(write)	  |	  Q  Q+15| ns
----------------------------------------------------------|--------------!-----
td(MSC)  MSC- valid from CLKOUT1			  ! -1	       9 | ns
===============================================================================



TIMING REQUIREMENTS OVER RECOMMENDED OPERATING CONDITIONS (See Note 1)
===============================================================================
		      PARAMETER				  | MIN	 NOM  MAX|UNIT
==========================================================|==============|=====
ta(A)	  Read data access time from address time	  |	    3Q-31| ns
	  (Notes 3 & 5)					  |		 |
----------------------------------------------------------|--------------|-----
tsu(D)R   Data read setup time before STRB- high          ! 17           ! ns
----------------------------------------------------------|--------------!-----
th(D)R	  Data read hold time from STRB- high		  ! 0		 ! ns
----------------------------------------------------------!--------------!-----
td(SL-R)  READY valid after STRB- low (no wait states)    !          Q-20! ns
----------------------------------------------------------!--------------!-----
td(C2H-R) READY valid after CLKOUT2 high                  !          Q-20! ns
----------------------------------------------------------!--------------|-----
th(SL-R)  READY hold time after STRB- low (no wait states)! Q-1 	 ! ns
----------------------------------------------------------!--------------!-----
th(C2H-R) READY hold after CLKOUT2 high 		  ! Q-1 	 ! ns
----------------------------------------------------------!--------------|-----
td(M-R)	  READY	valid after MSC- valid			  !	    2Q-20! ns
----------------------------------------------------------!--------------!-----
th(M-R)   READY hold time after MSC- valid		  ! 0		 ! ns
===============================================================================


			RS-, INT-, BIO-, AND XF	TIMING

SWITCHING CHARACTERISTICS OVER RECOMMENDED OPERATING CONDITIONS	(See Notes 1&6)
===============================================================================
		      PARAMETER				  ! MIN	 TYP  MAX!UNIT
==========================================================|==============|=====
td(RS)	  CLKOUT1 low to reset state entered		  |	       22| ns
----------------------------------------------------------|--------------|-----
td(IACK)  CLKOUT1 to IACK- valid			  ! -5		7! ns
----------------------------------------------------------|--------------|-----
td(XF)	  XF valid before falling edge of STRB-		  ! Q-8		 ! ns
===============================================================================


TIMING REQUIREMENTS OVER RECOMMENDED OPERATING CONDITIONS (See Notes 1&6)
================================================================================
		      PARAMETER				  | MIN	 NOM  MAX|UNIT
==========================================================|==============|======
tsu(IN)	 INT-,BIO-,RS- setup before CLKOUT1 high	  ! 22		 ! ns
----------------------------------------------------------|--------------|------
th(IN)	 INT-,BIO-,RS- hold after CLKOUT1 high		  ! 0		 | ns
----------------------------------------------------------|--------------|------
tf(IN)	 INT-,BIO- fall	time				  |		8| ns
----------------------------------------------------------|--------------|------
tw(IN)	INT-,BIO- low pulse duration			  | tc(C)	 | ns
----------------------------------------------------------|--------------|------
tw(RS)	RS- low	pulse duration				  |3tc(C)	 | ns
================================================================================



				 HOLD- TIMING

SWITCHING CHARACTERISTICS OVER RECOMMENDED OPERATING CONDITIONS	(See Note 1)
===============================================================================
		      PARAMETER				  ! MIN	 TYP  MAX!UNIT
==========================================================|==============|=====
td(C1L-AL)   HOLDA- low	after CLKOUT1 low		  ! 1	       11! ns
----------------------------------------------------------|--------------|-----
tdis(AL-A)   HOLDA- low	to address three-state		  |	  0	 | ns
----------------------------------------------------------|--------------|-----
tdis(C1L-A)  Address 3-state after CLKOUT1 low		  |	       20| ns
	     (HOLD- mode, Note 7)			  |		 |
----------------------------------------------------------|--------------|-----
td(HH-AH)    HOLD- high	to HOLDA- high			  !	       19! ns
----------------------------------------------------------|--------------|-----
ten(A-C1L)   Address driven before CLKOUT1 low		  |		8| ns
	     (HOLD- mode, Note 7)			  |		 |
===============================================================================


TIMING REQUIREMENTS OVER RECOMMENDED OPERATING CONDITIONS (See Note 1)
===============================================================================
		       PARAMETER			  | MIN	 NOM  MAX|UNIT
==========================================================|==============|=====
td(C2H-H)  HOLD- valid after CLKOUT2 high		  !	     Q-19! ns
===============================================================================


			       SERIAL PORT TIMING

SWITCHING CHARACTERISTICS OVER RECOMMENDED OPERATING CONDITIONS	(See Note 1)
===============================================================================
		       PARAMETER			   ! MIN  TYP  MAX|UNIT
===========================================================|==============|====
td(CH-DX)  DX valid after CLKX rising edge (Note 8)	   !		75! ns
-----------------------------------------------------------|-------------------
td(FL-DX)  DX valid after falling edge (TXM=0, Note 8)	   !		40! ns
-----------------------------------------------------------!--------------|----
td(CH-FS)  FSX valid after CLKX raising edge (TXM=1)	   !		40! ns
===============================================================================



TIMING REQUIRMENTS OVER	RECOMMENDED OPERATING CONDITIONS (See Note 1)
================================================================================
		       PARAMETER			   | MIN  NOM  MAX|UNIT
===========================================================|==============|=====
tc(SCK)	 Serial	port clock (CLKX,CLKR) cycle time (Note	10)| 160	  | ns
-----------------------------------------------------------|--------------|-----
tf(SCK)	 Serial	port clock (CLKX,CLKR) fall time	   |		25| ns
-----------------------------------------------------------|--------------|-----
tr(SCK)	 Serial	port clock (CLKX,CLKR) rise time	   |		25| ns
-----------------------------------------------------------|--------------|-----
tw(SCK)	 Serial	port clock (CLKX,CLKR) low pulse duration  | 64		  | ns
	 (Note 9)					   |		  |
-----------------------------------------------------------|--------------|-----
tw(SCK)	 Serial	port clock (CLKX,CLKR) high pulse duration | 64		  | ns
	 (Note 9)					   |		  |
-----------------------------------------------------------|--------------|-----
tsu(FS)  FSX,FSR setup time before CLKX,CLKR falling edge  ! 5		  ! ns
	 (TXM=0)					   |		  |
-----------------------------------------------------------|--------------|-----
th(FS)	 FSX,FSR hold time after CLKX,CLKR falling edge    ! 10 	  ! ns
	 (TXM=0)					   |		  |
-----------------------------------------------------------|--------------|-----
tsu(DR)  DR setup time before CLKR falling edge 	   !  5 	  ! ns
-----------------------------------------------------------!--------------!-----
th(DR)	 DR hold time after CLKR falling edge		   ! 10		  ! ns
================================================================================



PACKAGING

     The TMS320C25-50 is packaged in a 68-pin plastic leaded chip
     carrier.  Please refer to Appendix	A of "Second-Generation	TMS320
     User's Guide" for a complete package specification.



NOTES
================================================================================
   1:  Q = 1/4Tc(C)

   2:  CLKIN duty cycle	[tr(CI)	+ tw(CIH)]/tc(CI) must be within 40-60%

   3:  A15-A0, PS-, DS-, IS-, R/W, and BR- timings are all included in timings
       referenced as "address".

   4:  Delays between CLKOUT1,CLKOUT2 edges and	STRB- edges track each other,
       resulting in tw(SL) and tw(SH) being 2Q with no wait states.

   5:  Read data access	time is	defined	as  ta(A) = tsu(A) + tw(SL) - tsu(D)R.

   6:  RS-, INT-, and BIO- are asynchronous inputs and can occur at any	time
       during a	clock cycle.

   7:  A15-A0, PS-, DS-, STRB-,	and R/W	timings	are all	included in timings
       referenced as "address".

   8:  The last	occurence of FSX falling and CLKX rising.

   9:  The duty	cycle of the serial port must be within	40-60%

  10:  The minimum frequency at	which the serial port is tested	is
       1.25KHz.	 However, the serial port is fully static and will
       function	at arbitrarily low frequencies.






