SN54ABT18245

SCAN TEST DEVICE WITH 18-BIT BUS TRANSCEIVERS

SGBS307A – AUGUST 1994 – REVISED JANUARY 1995

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 SN54ABT18245 is characterized for operation over the full military temperature range of – 55

°C to 125°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