CY74FCT652T

2

BUS B

BUS A

GAB

L

GBA

L

CPAB

X

CPBA

X

SAB

X

SBA

L

BUS B

BUS A

GAB

X

L

L

GBA

H

X

H

CPAB

X

CPBA

X

SAB

X

X

X

SBA

X

X

X

BUS B

BUS A

GAB

H

GBA

H

CPAB

X

CPBA

X

SAB

L

SBA

X

BUS B

BUS A

GAB

H

GBA

L

CPAB

Hor L

CPBA

Hor L

SAB

H

SBA

H

Real-Time Transfer

Bus B to Bus A

Real-Time Transfer

Bus A to Bus B

Store Data from A and/or B

Transferred Stored Data

to A and/or B

Inputs

Data I/O

Operation or Function

GAB

GBA

CPAB

CPBA

SAB

SBA

L

L

H

H

H or L

H or L

X

X

X

X

Input

Input

Isolation

Store A and B Data

X

H

H

H

H or L

X

X

X

Input

Input

Output

Store A, Hold B

Store A in both registers

L

L

X

L

H or L

X

X

X

Output

Input

Input

Hold A, Store B

Store B in both registers

L

L

L

L

X

X

X

H or L

X

X

L

H

Output

Input

Real-Time B Data to A Bus

Stored B Data to A Bus

H

H

H

H

X

H or L

X

X

L

H

X

X

Input

Output

Real-Time A Data to B Bus

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

Notes:

1.

Select control=L: clocks can occur simultaneously. Select control=H: clocks must be staggered in order to load both registers.

H = HIGH Voltage Level. L = LOW Voltage Level. X = Don’t Care.

= LOW-to-HIGH Transition.

2.

The data output functions may be enabled or disabled by various signals at the GAB or GBA inputs. Data input functions are always enabled, i.e., data at the

bus pins will be stored on every LOW-to-HIGH transition on the clock inputs.