74HC194 Datasheet, PDF (4/10 Pages) NXP Semiconductors – 4-bit bidirectional universal shift register

Philips Semiconductors
4-bit bidirectional universal shift register
Product specification
74HC/HCT194
Fig.4 Functional diagram.
FUNCTION TABLE
INPUTS
OUTPUTS
OPERATING MODES
CP
MR
S₁
S₀
D_SR
D_SL
D_n
Q₀
Q₁
Q₂
Q₃
reset (clear)
X
L
X
X
X
X
X
L
L
L
L
hold (“do nothing”)
shift left
shift right
parallel load
X
H
I
I
X
X
X
q₀
q₁
q₂
q₃
↑
H
h
I
X
I
X
q₁
q₂
q₃
L
↑
H
h
I
X
h
X
q₁
q₂
q₃
H
↑
H
I
h
I
X
X
L
q₀
q₁
q₂
↑
H
I
h
h
X
X
H
q₀
q₁
q₂
↑
H
h
h
X
X
d_n
d₀
d₁
d₂
d₃
Notes
1. H = HIGH voltage level
h = HIGH voltage level one set-up time prior to the LOW-to-HIGH CP transition
L = LOW voltage level
I = LOW voltage level one set-up time prior to the LOW-to-HIGH CP transition
q,d = lower case letters indicate the state of the referenced input (or output) one set-up time prior to the
LOW-to-HIGH CP transition
X = don’t care
↑ = LOW-to-HIGH CP transition
December 1990
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