SN54ALS652, SN54ALS653, SN54AS651, SN54AS652

SN74ALS651A, SN74ALS652A, SN74ALS653, SN74ALS654, SN74AS651, SN74AS652

OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS

SDAS066F – DECEMBER 1983 – REVISED OCTOBER 1996

4

POST OFFICE BOX 655303

FUNCTION TABLES

SN54ALS653, SN54AS651,

SN74ALS651A, SN74ALS653, SN74AS651

INPUTS

DATA I/O†

OPERATION OR FUNCTION

OEAB

OEBA

CLKAB

CLKBA

SAB

SBA

A1– A8

B1– B8

OPERATION OR FUNCTION

L

H

H or L

H or L

X

X

Input

Input

Isolation

L

H

↑↑

X

X

Input

Input

Store A and B data

X

H

↑

H or L

X

X

Input

Unspecified‡

Store A, hold B

H

H

↑↑

X‡

X

Input

Output

Store A in both registers

L

X

H or L

↑

X

X

Unspecified‡

Input

Hold A, store B

L

L

↑↑

XX‡

Output

Input

Store B in both registers

L

L

X

X

X

L

Output

Input

Real-time B data to A bus

L

L

X

H or L

X

H

Output

Input

Stored B data to A bus

H

H

X

X

L

X

Input

Output

Real-time A data to B bus

H

H

H or L

X

H

X

Input

Output

Stored A data to B bus

H

L

H or L

H or L

H

H

Output

Output

Stored A data to B bus and

stored B data to A bus

† The data output functions may be enabled or disabled by a variety of level combinations at OEAB or OEBA. Data input functions are always

enabled; i.e., data at the bus terminals is stored on every low-to-high transition on the clock inputs.

‡ Select control = L; clocks can occur simultaneously.

Select control = H; clocks must be staggered to load both registers.

SN54ALS652, SN54AS652,

SN74ALS652A, SN74ALS654, SN74AS652

INPUTS

DATA I/O†

OPERATION OR FUNCTION

OEAB

OEBA

CLKAB

CLKBA

SAB

SBA

A1– A8

B1– B8

OPERATION OR FUNCTION

L

H

H or L

H or L

X

X

Input

Input

Isolation

L

H

↑↑

X

X

Input

Input

Store A and B data

X

H

↑

H or L

X

X

Input

Unspecified‡

Store A, hold B

H

H

↑↑

X‡

X

Input

Output

Store A in both registers

L

X

H or L

↑

X

X

Unspecified‡

Input

Hold A, store B

L

L

↑↑

XX‡

Output

Input

Store B in both registers

L

L

X

X

X

L

Output

Input

Real-time B data to A bus

L

L

X

H or L

X

H

Output

Input

Stored B data to A bus

H

H

X

X

L

X

Input

Output

Real-time A data to B bus

H

H

H or L

X

H

X

Input

Output

Stored A data to B bus

H

L

H or L

H or L

H

H

Output

Output

Stored A data to B bus and

stored B data to A bus

† The data output functions may be enabled or disabled by a variety of level combinations at OEAB or OEBA. Data input functions are always

enabled; i.e., data at the bus terminals is stored on every low-to-high transition on the clock inputs.

‡ Select control = L; clocks can occur simultaneously.

Select control = H; clocks must be staggered to load both registers.