GAB

A1

A2

B2

B1

TO OTHER SIX

TRANSCEIVERS

GBA

BLOCK DIAGRAM

1/4 LS623

5-1

FAST AND LS TTL DATA

OCTAL BUS TRANSCEIVER

WITH 3-STATE OUTPUT

The SN54 / 74LS623 series is an octal bus transceiver designed for

asynchronous two-way communication between data buses. Control function

implementation allows maximum timing flexibility. Enable inputs may be used

to disable the device so that buses are effectively isolated. Depending on the

Logic Levels at the enable inputs, Data transmission is allowed from the A bus

to the B bus or from the B bus to the A bus. The dual-enable configuration

gives the LS623 the capability to store data by simultaneous enabling of GBA

and GAB. Each output reinforces its input in this transceiver configuration.

Thus, when both control inputs are enabled all other data sources to the two

sets of bus lines (16 in all) will remain at their last states.

CONNECTION DIAGRAM (TOP VIEW)

18

17

16

15

14

13

1

2

3

4

5

6

7

20

19

8

VCC

ENABLE

GAB

ENABLE

GBA B1

B2

B3

B5

B4

B6

A1

A2

A3

A4

A5

A6

A7

9

10

A8

GND

12

11

B7

B8

FUNCTION TABLE

ENABLE INPUTS

OPERATION

GBA

GAB

LS623

L

L

B data to A bus

H

H

A data to B bus

H

L

Isolation

L

H

B data to A bus,

A data to B bus

H = HIGH Level, L = LOW Level, X = Irrelevant

SN54/74LS623

OCTAL BUS TRANSCEIVER

WITH 3-STATE OUTPUT

LOW POWER SCHOTTKY

ORDERING INFORMATION

SN54LSXXXJ

Ceramic

SN74LSXXXN

Plastic

SN74LSXXXDW SOIC

20

1

J SUFFIX

CERAMIC

CASE 732-03

20

1

N SUFFIX

PLASTIC

CASE 738-03

20

1

DW SUFFIX

SOIC

CASE 751D-03