SN54ABT18640, SN74ABT18640

SCAN TEST DEVICES

WITH 18-BIT INVERTING BUS TRANSCEIVERS

SCBS267C – FEBRUARY 1994 – REVISED JULY 1996

10

POST OFFICE BOX 655303

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.

During Capture-DR, the binary value 00000000000000001110000000101111 (0000E02F, hex) is captured in

the IDR to identify this device as Texas Instruments SN54/74ABT18640. The IDR order of scan is from TDI

through bits 31–0 to TDO. Table 2 shows the IDR 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).