Datasheet

SN54LVTH18504A, SN54LVTH182504A, SN74LVTH18504A, SN74LVTH182504A
3.3-V ABT SCAN TEST DEVICES
WITH 20-BIT UNIVERSAL BUS TRANSCEIVERS
SCBS667B – JULY 1996 – REVISED JUNE 1997
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Terminal Functions
TERMINAL NAME DESCRIPTION
A1–A20 Normal-function A-bus I/O ports. See function table for normal-mode logic.
B1–B20 Normal-function B-bus I/O ports. See function table for normal-mode logic.
CLKAB, CLKBA Normal-function clock inputs. See function table for normal-mode logic.
CLKENAB, CLKENBA Normal-function clock enables. See function table for normal-mode logic.
GND Ground
LEAB, LEBA Normal-function latch enables. See function table for normal-mode logic.
OEAB, OEBA
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 Std 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 Std 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 Std 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 Std 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