AT16646

Fast Logic

™

™

16-Bit

Tri-State

™

™

Register

AT16646F

AT16646G

Features

(G grade)

Description

Atmel’s AT16646 devices are 16-bit high speed, low power Tri-statable D type

registers, ideal for use in systems requiring both transparent and registered mode

functions. They are organized as two separate 8-bit bus transceivers. Data flow is

bi-directional, and can be controlled for multiplexed transmission between A bus and

B bus either directly or from the D registers by use of the direction control pin (xDir),

output enable (xOE), and select lines (xSAB and xSBA). Storage of data on the A bus

and B bus is controlled by the output pins. They have very low ground bounce and

excellent input noise rejection, giving the user stable signals in a high speed

environment. The Bus Hold feature eliminates the need for pull-up or pull-down

resistors and retains the last active state during a Tri-State event.

Functional Block Diagram

Pin Names

Descriptions

xDir, xOE

Output Enable Inputs

xCLKAB,xCLKBA

Clock Pulse Inputs

xSAB, xSBA

Output Data Source Select Inputs

xA

χ

Data Register A Inputs

Data Register B Outputs

xB

χ

Data Register B Inputs

Data Register A Outputs

Pin Configurations

1

3

5

7

9

11

13

15

17

19

21

23

25

27

55

53

51

49

47

45

43

41

39

37

35

33

31

29

56

54

52

50

48

46

44

42

40

38

36

34

32

30

2

4

6

8

10

12

14

16

18

20

22

24

26

28

1CLKAB

GND

1A2

1A3

1A5

1A6

1A8

2A2

GND

2A5

VCC

2A8

2SAB

2DIR

1

1SBA

1B1

VCC

1B4

GND

1B7

2B1

2B3

2B4

2B6

2B7

GND

2CLKBA

OE

1CLKBA

GND

1B2

1B3

1B5

1B6

1B8

2B2

GND

2B5

VCC

2B8

2SBA

2OE

1DIR

1SAB

1A1

VCC

1A4

GND

1A7

2A1

2A3

2A4

2A6

2A7

GND

2CLKAB

SSOP/TSSOP

Top View

0757B

AT16646

5-21