Preliminary W89C982AF

- 8 -

BLOCK DIAGRAM

Twisted Pair Line

Transceiver 1

Port Partition/

Reconnection

Logic

Rx MUX

PLL

Decoder

MUX

Timer and

Counters

.

.

.

.

Main state

Machine

and

Glue logic

FIFO

Control

Logic

FIFO

Inter-IMPR II

Interface

Preamble/

JAM

Generator

Jabber lockup and

Fragment extension

Logic

.

.

Twisted Pair Line

Transceiver 8

Encoder and

Transmitter

Logic

Tx MUX

Management

Logic

AUI

Interface

Management

Interface

Port status

direct report

FUNCTIONAL DESCRIPTION

The Integrated Multiple Port Repeater II implements the functions stipulated in the IEEE repeater

specifications, the functions specified by 10BASE-T standards, and functions for network

management. It provides an Inter-IMPR II interface to allow implementation of a repeater set with

more network ports. The block functions of the IMPR II are described below.

AUI Interface and Twisted Pair Line Transceiver

The AUI provides an interface for an external Medium Attached Unit (MAU) connected to the IMPR II.

The IMPR II can be used to connect a 10BASE2 or 10BASE5 Ethernet to a 10BASE-T Ethernet via a

coaxial transceiver. The Twisted Pair Line Transceiver provides the interface used to connect IEEE

802.3 LAN stations (Data Terminal Equipment, or DTEs) into Ethernet networks constructed from

twisted pair media. The Twisted Pair Line Transceiver also contains a link test function and

autopolarity reversal function for wiring detection.

Link Test Function

The link test function of the TP port is used to check whether the TP port is linked to an active TP

port. The TP port will enter link fail state if it does not receive any packets or link test pulses for more

than 60 mS, until it receives either six consecutive link pulses or a packet. When the TP port is in link