Truth Table

‘‘A’’ Enable

PS

AB

AS

Mode

Operation

0

0

0

X

Serial

Synchronous Serial data input A- and B-Parallel data outputs disabled

0

0

1

X

Serial

Synchronous Serial data input B-Parallel data output

0

1

0

0

Parallel

B Synchronous Parallel data inputs A-Parallel data outputs disabled

0

1

0

1

Parallel

B Asynchronous Parallel data inputs A-Parallel data outputs disabled

0

1

1

0

Parallel

A-Parallel data inputs disabled B-Parallel data outputs synchronous data recirculation

0

1

1

1

Parallel

A-Parallel data inputs disabled B-Parallel data outputs asynchronous data recirculation

1

0

0

X

Serial

Synchronous Serial data input A-Parallel data output

1

0

1

X

Serial

Synchronous Serial data input B-Parallel data output

1

1

0

0

Parallel

B Synchronous Parallel data input A-Parallel data output

1

1

0

1

Parallel

B Asynchronous Parallel data input A-Parallel data output

1

1

1

0

Parallel

A Synchronous Parallel data input B-Parallel data output

1

1

1

1

Parallel

A Asynchronous Parallel data input B-Parallel data output

10