AM79C90 Datasheet, PDF (1/62 Pages) Advanced Micro Devices – CMOS Local Area Network Controller for Ethernet (C-LANCE)

PRELIMINARY
Am79C90
CMOS Local Area Network Controller for Ethernet
(C-LANCE)
DISTINCTIVE CHARACTERISTICS
s Compatible with Ethernet and IEEE 802.3
10BASE-5 Type A, and 10BASE-2 Type B,
“Cheapernet,” 10BASE-T
s Easily interfaced with 80x86, 680x0, Am29000^®,
Z8000^™ microprocessors
s On-board DMA and buffer management, 64-byte
Receive, 48-byte Transmit FIFOs
s 24-bit-wide linear addressing (Bus Master Mode)
s Network and packet error reporting
s Back-to-back packet reception with as little as
0.5 µs interframe spacing
s Diagnostic Routines
— Internal/external loopback
— CRC logic check
— Time domain reflectometer
s Low power consumption for power-sensitive
applications
s Completely software- and hardware-compatible with
AMD’s LANCE device (Am7990) (see Appendix A)
GENERAL DESCRIPTION
The Am79C90 CMOS Local Area Network Controller
for Ethernet (C-LANCE) is a 48-pin VLSI device de-
signed to greatly simplify interfacing a microcomputer or
minicomputer to an IEEE 802.3/Ethernet Local Area
Network. The C-LANCE, in conjunction with the
Am7992B Serial Interface Adapter (SIA), Am7996 or
Am79C98 and Am79C100 Transceiver, and closely
coupled local memory and microprocessor, is intended
to provide the user with a complete interface module for
an Ethernet network. The Am79C90 is designed using
a scalable CMOS technology and is compatible with a
variety of microprocessors. On-board DMA, advanced
buffer management, and extensive error reporting and
diagnostics facilitate design and improve system
performance.
BLOCK DIAGRAM
DAL15:0
A23:16
Parallel
Bus
Interface
DMA/Data
Path Control
Microprogram
Store
INTR
HOLD
HLDA
ALE/AS
CS
ADR
DAS
DALO
DALI
READ
BM0/BYTE
BM1/BUSAKO
READY
RESET
C-LANCE/
CPU
Control
Bus
Interface
Station
Address
Detection
Retry
Logic
Serial I/O
Interface
RX
RCLK
TX
TCLK
CLSN
TENA
RENA
17881C-1
Publication# 17881 Rev: C Amendment/0
Issue Date: January 1998
This document contains information on a product under development at Advanced Micro Devices. The
information is intended to help you evaluate this product. AMD reserves the right to change or discontinue
1
work on this proposed product without notice.