GENERAL DESCRIPTION

The LAN91C94 is a VLSI Ethernet Controller that combines ISA and PCMCIA interfaces in one chip. LAN91C94 integrates all the MAC and physical layer functions, as well as the packet RAM, needed to implement a high performance 10BASE-T (twisted pair) node. For 10BASE5 (thick coax), 10BASE2 (thin coax), and 10BASE-F (fiber) implementations, the LAN91C94 interfaces to external transceivers via its AUI port. Only one additional IC is required on most applications. The LAN91C94 occupies 16 I/0 locations and no memory space except for PCMCIA attribute memory space.

FEATURES

• ISA/PCMCIA Single-Chip Ethernet Controller

• 4608 Bytes of On-Chip RAM

• Supports IEEE 802.3 (ANSI 8802-3) Ethernet Standards

• Simultasking TM - Early Transmit and Early Receive Functions

• Hardware Memory Management Unit

• Optional Configuration via Serial EEPROM Interface (Jumperless)

• Single +5V Power Supply

• Low Power CMOS Design

• 100 Pin QFP, TQFP and VTQFP Package

Bus Interface

• Direct Interface to ISA and PCMCIA with No Wait States

• Flexible Bus Interface

• 16-Bit Data and Control Paths

• Fast Access Time (40 ns)

• Pipelined Data Path

• Handles Block Word Transfers for Any Alignment

• High Performance Chained (Back-toBack) Transmit and Receive

• Pin Compatible with LAN91C92 (in ISA mode)

• Flat Memory Structure for Low CPU Overhead

• Dynamic Memory Allocation Between Transmit and Receive

• Buffered Architecture, Insensitive to Bus Latencies (No Overruns/Underruns)

• Supports Boot PROM for Diskless ISA Applications

Network Interface

• Integrates 10BASE-T Transceiver Functions:

- Driver and Receiver

- Link Integrity Test

- Receive Polarity Detection and Correction

• Integrates AUI Interface

• Implements 10 Mbps Manchester Encoding/Decoding and Clock Recovery

• Automatic Retransmission, Bad Packet Rejection, and Transmit Padding

• External and Internal Loopback Modes

• Four Direct Driven LEDs for Status/Diagnostics

Software Drivers

• Uses Certified LAN9000 Drivers Which Operate with Every Major Network Operating System

• Software Driver Compatible with LAN91C92 and LAN91C100 (100 Mbps) Controllers in ISA Mode

• Software Driver Utilizes Full Capability of 32 Bit Microprocessor