September 1993

4

Philips Semiconductors

Product specification

Octal bus transceiver/register; 3-state

74HC/HCT652

FUNCTION TABLE

Notes

1. H = HIGH voltage level

L = LOW voltage level

X = don’t care

↑ = LOW-to-HIGH transition

functions are always enabled, i.e., data at the bus inputs will be stored on every LOW-to-HIGH transition on the clock

inputs.

OPERATION OR FUNCTION

HC/HCT652

L

H

H or L

H or L

X

X

Input

Input

Isolation

LH

↑↑

X

X

Store A and B data

XH

↑

H or L

X

X

Input

Not specified

Store A, Hold B

HH

↑↑

L

X

Input

Output

Store A in both registers

L

X

H or L

↑

X

X

Not specified

Input

Hold A, Store B

LL

↑↑

X

L

Ouput

Input

Store B in both registers

LL

X

X

X

L

Ouput

Input

Real Time B Data to A Bus

L

L

X

H or L

X

H

Stored B Data to A Bus

HH

X

X

L

X

Input

Output

Real Time A Data to B Bus

H

H

H or L

X

H

X

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

Fig.4 Functional diagram.