Datasheet

SN54ABTH18502A, SN54ABTH182502A, SN74ABTH18502A, SN74ABTH182502A
SCAN TEST DEVICES
WITH 18-BIT UNIVERSAL BUS TRANSCEIVERS
SCBS164E – AUGUST 1993 – REVISED DECEMBER 1996
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Terminal Functions
TERMINAL NAME DESCRIPTION
1A1–1A9,
2A1–2A9
Normal-function A-bus I/O ports. See function table for normal-mode logic.
1B1–1B9,
2B1–2B9
Normal-function B-bus I/O ports. See function table for normal-mode logic.
1CLKAB, 1CLKBA,
2CLKAB, 2CLKBA
Normal-function clock inputs. See function table for normal-mode logic.
GND Ground
1LEAB, 1LEBA,
2LEAB, 2LEBA
Normal-function latch enables. See function table for normal-mode logic.
1OEAB, 1OEBA,
2OEAB
, 2OEBA
Normal-function output enables. See function table for normal-mode logic. An internal pullup at each terminal forces the
terminal to a high level if left unconnected.
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 directs the device through its TAP
controller states. An internal pullup forces TMS to a high level if left unconnected.
V
CC
Supply voltage