Datasheet

SN54ABT8245, SN74ABT8245
SCAN TEST DEVICES
WITH OCTAL BUS TRANSCEIVERS
SCBS124D – AUGUST 1992 – REVISED DECEMBER 1996
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
description (continued)
In the test mode, the normal operation of the SCOPE bus transceivers is inhibited and the test circuitry is
enabled to observe and control the I/O boundary of the device. When enabled, the test circuitry can perform
boundary-scan test operations as described in IEEE Standard 1149.1-1990.
Four dedicated test pins 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 SN54ABT8245 is characterized for operation over the full military temperature range of – 55°C to 125°C.
The SN74ABT8245 is characterized for operation from –40°C to 85°C.
FUNCTION TABLE
(normal mode)
INPUTS
OPERATION
OE DIR
OPERATION
L L B data to A bus
L H A data to B bus
H X Isolation