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Functional Description

The AC/ACT399 is a high-speed quad 2-port register. It

selects four bits of data from either of two sources (Ports)

under control of a common Select input (S). The selected

data is transferred to a 4-bit output register synchronous

with the LOW-to-HIGH transition of the Clock input (CP).

The 4-bit D-type output register is fully edge-triggered. The

only a setup time prior to and hold time after the LOW-to-

HIGH transition of the Clock input for predictable operation.

Function Table

H

= HIGH Voltage Level

L

= LOW Voltage Level

X

= Immaterial

 = LOW-to-HIGH Clock Transition

Logic Diagram

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.

Inputs

Outputs

CP

Q

Q

LL

X



LH

LH

X



HL

HX

L



LH

HX

H



HL