Datasheet
SN54LVTH18646A, SN54LVTH182646A, SN74LVTH18646A, SN74LVTH182646A
3.3-V ABT SCAN TEST DEVICES
WITH 18-BIT TRANSCEIVERS AND REGISTERS
SCBS311D – MARCH 1994 – REVISED JUNE 1997
13
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
device-identification register
The device-identification register (IDR) is 32 bits long. It can be selected and read to identify the manufacturer,
part number, and version of this device.
For the ’LVTH18646A, the binary value 00100000000000011110000000101111 (2001E02F, hex) is captured
(during Capture-DR state) in the device-identification register to identify this device as TI SN54/74LVTH18646A.
For the ’LVTH182646A, the binary value 00100000000000100011000000101111 (2002302F, hex) is captured
(during Capture-DR state) in the device-identification register to identify this device as TI
SN54/74LVTH182646A.
The device-identification register order of scan is from TDI through bits 31–0 to TDO. Table 2 shows the device
identification register bits and their significance.
Table 2. Device-Identification Register Configuration
IDR BIT
NUMBER
IDENTIFICATION
SIGNIFICANCE
IDR BIT
NUMBER
IDENTIFICATION
SIGNIFICANCE
IDR BIT
NUMBER
IDENTIFICATION
SIGNIFICANCE
31 VERSION3 27 PARTNUMBER15 11 MANUFACTURER10
†
30 VERSION2 26 PARTNUMBER14 10 MANUFACTURER09
†
29 VERSION1 25 PARTNUMBER13 9 MANUFACTURER08
†
28 VERSION0 24 PARTNUMBER12 8 MANUFACTURER07
†
–– –– 23 PARTNUMBER11 7 MANUFACTURER06
†
–– –– 22 PARTNUMBER10 6 MANUFACTURER05
†
–– –– 21 PARTNUMBER09 5 MANUFACTURER04
†
–– –– 20 PARTNUMBER08 4 MANUFACTURER03
†
–– –– 19 PARTNUMBER07 3 MANUFACTURER02
†
–– –– 18 PARTNUMBER06 2 MANUFACTURER01
†
–– –– 17 PARTNUMBER05 1 MANUFACTURER00
†
–– –– 16 PARTNUMBER04 0 LOGIC1
†
–– –– 15 PARTNUMBER03 –– ––
–– –– 14 PARTNUMBER02 –– ––
–– –– 13 PARTNUMBER01 –– ––
–– –– 12 PARTNUMBER00 –– ––
†
Note that for TI products, bits 11–0 of the device-identification register always contain the binary value 000000101111
(02F, hex).