LANtastic for ARTISOFT Artisoft Technical Bulletin TITLE: AE-3 Ethernet Adapter Low-Level Information FILENAME: AE3.TXT UPDATED: 04.30.95 CLASSIFICATION: Network interface card AUTHOR: The Artisoft AE-3 Ethernet Adapter, uses the National Semiconductor 83902 Network Interface Controller (ST-NIC). This document assumes the reader has access to the National Semiconductor Data Communications LAN Handbook. This book contains information on the 83902 chipset, application notes and 802.3 specifications. NIC Registers The 8 bit 8390 internal registers are mapped into PC I/O space. The base address is jumper selectable on the AE-3 card. The I/O bases 300h, 320h, 340h or 360h are available. The base address is the address where the NIC command register will be mapped into PC I/O space. The AE-3 will decode a block of 32 I/O ports, starting at the selected base address. The first 16 ports will be the NIC internal registers. For example, if you select an I/O base of 320h, the NIC command register will be at 320h and the NIC ISR (Interrupt Status Register) will be at I/O base + 7h or 327h. Data Port All data to and from the network must pass through the data port. The data port is located at I/O base + 10h. The data port is controlled by the NIC Remote DMA. All read/writes to the data port cause a remote DMA cycle in the NIC. If the NIC is in 8 bit mode, the data port is an 8 bit port. If the NIC is in 16 bit mode, the data port is 16 bits wide. Always make sure to use the proper size instruction when transferring data to or from the AE-3. For example, if you are running in 16 bit mode, use INSW rather than the INSB to string-move the data. Always take care to insure that the NIC Remote DMA count is the same as the number of bytes you will be moving. If the NIC Remote DMA count reaches 0 and the driver issues another in/out instruction, the AE-3 will lock up the host PC by deasserting IOCHREADY. NIC Reset A complete reset of the NIC is performed by writing a byte to I/O base + 17h. It is recommended that you issue a reset before performing any action on the NIC. Onboard RAM The onboard RAM is mapped into NIC address space as follows: 8K RAMs 32K RAMs 8 bit mode 40h - 5Fh 01h - 7Fh 16 bit mode 40h - 7Fh 01h - FEh Notes: The NIC addresses are given in NIC page format. If Novell emulation mode is selected (W10), 32K RAMs will appear as 8K RAMs. Ethernet IEEE 802.3 Address The unique 6 byte Ethernet Address of each AE-3 is contained in an onboard PROM. The PROM is mapped into NIC address space at page 00. Always use 8 bit mode on the NIC to read this PROM. The format of the PROM is as follows: A0 A0 A1 A1 A2 A2 A3 A3 A4 A4 A5 A5 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 MM MM MM MM The IEEE Ethernet address is contained in A0 through A5. The mode byte (MM) is for determining if the AE-3 is in an 8 bit or a 16 bit slot. If MM = 57h (ASCII "W"), the AE-3 is in a 16 bit (word) slot. If MM = 42h (ASCII "B"), the AE-3 is in an 8 bit (byte) slot, or the 8 bit override jumper (W9) is selected. DMA Operation Direct Memory Access (DMA) can be used to transfer data on and off the AE-3 adapter instead of the data port. Onboard jumpers allow selection of 8 bit DMA channels 1 and 3 or 16 bit channels 5 and 7. ARTISOFT, Inc. makes no warranties as to the completeness or accuracy of this document. LANtastic is a trademark of ARTISOFT, Inc. Brand names, company names, and product names are trademarks or registered trademarks of their respective companies. We have several methods, you can use to receive support. Our normal technical support line is 520-670-7000 (7a-5p MT). You can post a message on CompuServe in the Artisoft Forum. CompuServe is answered in 1 business day (if left before 6am MT). You can post a message on the Arti-Facts BBS @ 520-884-8648 or 520-884-9675 (14.4k) [8,n,1]. For immediate access to a technician, you can contact our Express Service @ $2.50/minute with extended hours of 6a-9p MT and 6a-5p MT on Saturday. Express service can be obtained at 1-900-555-8324 (billed to phone) or 1-800-293-3936 with a valid AmEx, MC, or VISA card. Please Note During Daylight Savings our Times are 1 hour earlier.