SN54LVTH18646A, SN54LVTH182646A, SN74LVTH18646A, SN74LVTH182646A

3.3-V ABT SCAN TEST DEVICES

WITH 18-BIT TRANSCEIVERS AND REGISTERS

SCBS311D – MARCH 1994 – REVISED JUNE 1997

3

POST OFFICE BOX 655303

18 19

48

47

46

45

44

43

42

41

40

39

38

37

36

35

34

33

20

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

21 22 23 24

63 62 61 60 59

64

58

56 55 54

57

25 26 27 28 29

53 52

17

51 50 49

30 31 32

1A3

1A4

1A5

GND

1A6

1A7

1A8

1A9

2A1

2A2

2A3

GND

2A4

2A5

2A6

1B4

1B5

1B6

GND

1B7

1B8

1B9

2B1

2B2

2B3

2B4

GND

2B5

2B6

2B7

SN74LVTH18646A, SN74LVTH182646A . . . PM PACKAGE

(TOP VIEW)

FUNCTION TABLE

(normal mode, each 9-bit section)

INPUTS

DATA I/O

OPERATION OR FUNCTION

OE

DIR

CLKAB

CLKBA

SAB

SBA

A1–A9

B1–B9

OPERATION OR FUNCTION

X

X

↑

X

X

X

Input

Unspecified†

Store A, B unspecified†

X

XX

↑

X

X

Unspecified†

Input

Store B, A unspecified†

H

X

↑

↑

X

X

Input

Input

Store A and B data

H

X

L

L

X

X

Input disabled

Input disabled

Isolation, hold storage

L

L

X

X

X

L

Output

Input

Real-time B data to A bus

L

L

X

X

X

H

Output

Input disabled

Stored B data to A bus

L

H

X

X

L

X

Input

Output

Real-time A data to B bus

L

H

X

X

H

X

Input disabled

Output

Stored A data to B bus

† The data-output functions can be enabled or disabled by various signals at OE and DIR. Data-input functions are always enabled; i.e., data at

the bus terminals is stored on every low-to-high transition of the clock inputs.