SN54ABT18245A, SN74ABT18245A

SCAN TEST DEVICES

WITH 18-BIT BUS TRANSCEIVERS

SCBS110H – AUGUST 1992 – REVISED FEBRUARY 1999

2

POST OFFICE BOX 655303

description (continued)

Four dedicated test pins observe and control the operation of the test circuitry: test-data input (TDI), test-data

output (TDO), test-mode select (TMS), and test clock (TCK). Additionally, the test circuitry performs other testing

functions such as parallel-signature analysis (PSA) on data inputs and pseudo-random pattern generation

(PRPG) from data outputs. All testing and scan operations are synchronized to the TAP interface.

The SN54ABT18245A is characterized for operation over the full military temperature range of –55

°C to 125°C.

The SN74ABT18245A is characterized for operation from –40

°C to 85°C.

FUNCTION TABLE

(normal mode, each 9-bit section)

INPUTS

OPERATION

OE

DIR

OPERATION

L

L

B data to A bus

L

H

A data to B bus

H

X

Isolation