Functional Description
Truth Table
The VHC573 contains eight D-type latches with 3-STATE
output buffers. When the Latch Enable (LE) input is HIGH,
Inputs
data on the Dn inputs enters the latches. In this condition
OE
LE
D
the latches are transparent, i.e., a latch output will change
state each time its D input changes. When LE is LOW the
L
H
H
latches store the information that was present on the D
L
H
L
inputs, a setup time preceding the HIGH-to-LOW transition
of LE. The 3-STATE buffers are controlled by the Output
L
L
X
Enable (OE) input. When OE is LOW, the buffers are
H
enabled. When OE is HIGH the buffers are in the high
X
X
impedance mode, but, this does not interfere with entering H = HIGH Voltage Level
new data into the latches.
L = LOW Voltage Level
X = Immaterial
Z = High Impedance
Logic Diagram
Outputs
On
H
L
O0
Z
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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