M54HC190 Datasheet, PDF (2/14 Pages) STMicroelectronics – 4 BIT SYNCHRONOUS UP/DOWN COUNTERS

M54/M74HC190/191
INPUT AND OUTPUT EQUIVALENT CIRCUIT
IEC LOGIC SYMBOL (HC190)
PIN DESCRIPTION
PIN No
3, 2, 6, 7
4
5
11
12
13
14
15, 1, 10, 9
8
16
SYMBOL NAME AND FUNCTION
QA to QD Flip-Flop Outputs
ENABLE Count Enable Input
(Active LOW)
U/D
Parallel Data Input
LOAD Load Input (Active LOW)
MA/MI OUT Terminal Count Output
RC
Ripple Clock Output
(Active LOW)
CLOCK
Cloack Input (LOW to
HIGH, Edge-triggered)
DA to DD Data Inputs
GND
Ground (0V)
VCC
Positive Supply Voltage
IEC LOGIC SYMBOL (HC191)
TRUTH TABLE
INPUTS
OUTPUS
LOAD ENABLE
D/U
CLOCK
QA
QB
QC
QD
L
X
X
X
a
b
c
d
H
L
L
UP COUNT
H
L
H
DOWN COUNT
H
H
X
NO CHANGE
H
X
X
NO CHANGE
X: Don’t Care
a - d: The level of steady state inputs at inputs a through D respectively
FUNCTION
PRESET DATA
UP COUNT
DOWN COUNT
NO COUNT
NO COUNT
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