SN54ABT8245, SN74ABT8245

SCAN TEST DEVICES

WITH OCTAL BUS TRANSCEIVERS

SCBS124D – AUGUST 1992 – REVISED DECEMBER 1996

4

POST OFFICE BOX 655303

Terminal Functions

TERMINAL

NAME

DESCRIPTION

A1 – A8

Normal-function A-bus I/O ports. See function table for normal-mode logic.

B1 – B8

Normal-function B-bus I/O ports. See function table for normal-mode logic.

DIR

Normal-function direction-control input. See function table for normal-mode logic.

GND

Ground

OE

Normal-function output-enable input. See function table for normal-mode logic.

TCK

Test clock. One of four terminals required by IEEE Standard 1149.1-1990. Test operations of the device are synchronous to TCK.

Data is captured on the rising edge of TCK and outputs change on the falling edge of TCK.

TDI

Test data input. One of four terminals required by IEEE Standard 1149.1-1990. TDI is the serial input for shifting data through the

instruction register or selected data register. An internal pullup forces TDI to a high level if left unconnected.

TDO

Test data output. One of four terminals required by IEEE Standard 1149.1-1990. TDO is the serial output for shifting data through

the instruction register or selected data register.

TMS

Test mode select. One of four terminals required by IEEE Standard 1149.1-1990. TMS input directs the device through its TAP

controller states. An internal pullup forces TMS to a high level if left unconnected.

VCC

Supply voltage