Datasheet
SN54LVTH18646A, SN54LVTH182646A, SN74LVTH18646A, SN74LVTH182646A
3.3-V ABT SCAN TEST DEVICES
WITH 18-BIT TRANSCEIVERS AND REGISTERS
SCBS311D – MARCH 1994 – REVISED JUNE 1997
6
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.
1DIR, 2DIR Normal-function direction controls. See function table for normal-mode logic.
GND Ground
1OE, 2OE
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.
1SAB, 1SBA,
2SAB, 2SBA
Normal-function select controls. See function table for normal-mode logic.
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