Functional Description

The ’ACT573 contains eight D-type latches with TRI-STATE

output buffers. When the Latch Enable (LE) input is HIGH,

data on the D

latches are transparent, i.e., a latch output will change state

each time its D input changes. When LE is LOW the latches

store the information that was present on the D inputs a

setup time preceding the HIGH-to-LOW transition of LE. The

TRI-STATE buffers are controlled by the Output Enable (OE)

input. When OE is LOW, the buffers are enabled. When OE

is HIGH the buffers are in the high impedance mode but this

does not interfere with entering new data into the latches.

Truth Table

Inputs

Outputs

OE

LE

D

O

n

LH

H

H

LH

L

L

LL

X

O

0

HX

X

Z

H = HIGH Voltage

L = LOW Voltage

Z = High Impedance

X = Immaterial

Logic Diagram

DS100332-5

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

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