SN75LBC088

AUI CONCENTRATOR

SLLS150A – DECEMBER 1992 – REVISED MAY 1993

2–5

POST OFFICE BOX 655303

Terminal Functions

TERMINAL

I/O

DESCRIPTION

NAME

NO.

I/O

DESCRIPTION

CLK –

3

O

Clock output. Output for an external series-resonant 10-MHz crystal required for internal timing.

CLK +

2

I

Clock input. Input for an external series-resonant 10-MHz crystal required for internal timing. The CLK+

accepts an external TTL level clock also.

DRVDDx

4, 14, 25, 35,

46, 56, 67, 77

VDD power supply. These terminals provide power to the drivers.

DRVSSx

9, 19, 30, 40,

51, 61, 72, 82

VSS power ground. These terminals provide a ground return for the driver circuits.

GCL –

64

I

Global collision. Differential inputs that receive the network collision status for forwarding to the

GCL +

63

I

individual station ports.

GLOBAL

1

I/O

Global. This is a bidirectional terminal. When functioning as an output, the chip is in a test mode and

monitors internal nodes that are multiplexed to it. When functioning as an input, the terminal is pulled

low (LOCAL held high) and the station ports are connected to the LAN. This terminal is held inactive

(high) with an internal pullup resistor.

GRX –

42

I

Global receive. Differential inputs that receive network data from an external transceiver and route it

GRX +

41

I

to all eight station ports.

GTX –

24

O

Global transmit. Differential outputs that transmit data from one of eight station ports to the network.

GTX +

23

O

LOCAL

66

I

Local. When in local mode, this terminal is pulled low (GLOBAL held high) and the station ports are

disconnected from the LAN. This terminal is held inactive (high) with an internal pullup resistor.

RCVDD1

20

VDD power supply. These terminals provide power to the receivers.

RCVDD2

62

RCVSS1

21

VSS power ground. These terminals provide a ground return for receivers.

RCVSS2

65

SCLx –

8, 16, 29, 37

50, 58, 71, 79

O

Station port collision. Differential outputs that transmit the collision condition to the station. When during

any station transmit activity one or more additional stations become active, the device recognizes this

SCLx +

7, 15, 28, 36,

49, 57, 70, 78

O

as a collision. The device then places a 10-MHz collision signal on all of the SCLx output drivers.

SRX –

11, 13, 32, 34,

53, 55, 74, 76

I

Station port receive. Differential input for receiving data from the station to the network.

SRX +

10, 12, 31, 33,

52, 54, 73, 75

I

STX –

6, 18, 27, 39,

48, 60, 69, 81

O

Station port transmit. Differential output for transmitting network data to the the station.

STX +

5, 17, 26, 38,

47, 59, 68, 80

O

SMARTSQE

22

I

This input enables the smart SQE circuitry. In normal operating mode, this enables the SMARTSQE

test function performed at the end of a data packet transmission. In the test mode, SMARTSQE works

with TEST to place the chip into a special mode. This terminal is held inactive (high) with an internal

pullup resistor.

TEST

45

I

Test. To invoke the self-exerciser test mode, this terminal and GLOBAL are enabled.

VDD(L)

43, 84

VDD logic power supply. These terminals provide power to the CMOS logic.

VSS(L)

44, 83

VSS logic ground. These terminals provide power to a ground return for the CMOS logic.