CD54AC191 Datasheet, PDF (2/10 Pages) Texas Instruments – Presettable Synchronous 4-Bit Binary Up/Down Counter

CD54AC191, CD54ACT191
Functional Diagram
BINARY
PRESET
P0 P1 P2 P3
15 1 10 9
ASYN. PARALLEL 11
LOAD ENABLE
CLOCK ¹⁴
3 _Q0
2 _Q1
6 _Q2
BINARY
OUTPUTS
UP/DOWN ⁵
COUNT 4
ENABLE
7 _Q3
12 TERMINAL
COUNT
13 _{RIPPLE CLOCK}
TRUTH TABLE
INPUTS
PL
CE
U/D
CP
FUNCTION
H
L
L
↑
Count Up
H
L
H
↑
Count Down
L
X
X
X
Asynchronous Preset
H
H
X
X
No Change
U/D or CE should be changed only when clock is high.
X = Don’t Care
↑ = Low-to-High clock transition.
2