1

2

3

4

5

6

7

8

9

10

11

12

13

14

28

27

26

25

24

23

22

21

20

19

18

17

16

15

G

A1

A2

A3

A4

GND

GND

GND

GND

A5

A6

A7

A8

DIR

CAB

SAB

B1

B2

B3

B4

B5

B6

B7

B8

CBA

SBA

DW PACKAGE

(TOP VIEW)

74ACT11646

OCTAL BUS TRANSCEIVER AND REGISTER

WITH 3STATE OUTPUTS

SCAS061A − D2957, JULY 1987 − REVISED APRIL 1993

POST OFFICE BOX 655303

POST OFFICE BOX 1443

Copyright

2−1

PCB Layout

Minimize High-Speed Switching Noise

CMOS) 1-

mm Process

description

These devices consist of bus transceiver circuits,

3-state outputs, D-type flip-flops, and control

circuitry arranged for multiplexed transmission of

data directly from the data bus or from the internal

storage registers. Data on the A or B bus will be

clocked into the registers on the low-to-high

transition of the appropriate clock pin (CAB or

CBA). Figure 1 illustrates the four fundamental

bus-management functions that can be performed

with the octal bus transceivers and registers.

Enable (G) and direction (DIR) pins are provided to control the transceiver functions. In the transceiver mode,

data present at the high-impedance port may be stored in either register or in both. The select controls (SAB

and SBA) can multiplex stored and real-time (transparent mode) data. The circuitry used for select control will

eliminate the typical decoding glitch which occurs in a multiplexer during the transition between stored and

real-time data. The direction control determines which bus will receive data when enable G is active (low). In

the isolation mode (control G high), A data may be stored in one register and/or B data may be stored in the

other register.

When an output function is disabled, the input function is still enabled and may be used to store and transmit

data. Only one of the two buses, A or B, may be driven at a time.

The 74ACT11646 is characterized for operation from − 40

°C to 85°C.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

EPIC is a trademark of Texas Instruments Incorporated.