M74HC590

2/15

INPUT AND OUTPUT EQUIVALENT CIRCUIT

PIN DESCRIPTION

TRUTH TABLE

X: Don’t Care

RCO = QA’·QB’·QC’·QD’·QE’·QF’·QG’·QH’ (QA’ to QH’ : INTERNAL OUTPUTS OF THE COUNTER)

LOGIC DIAGRAM

PIN No

SYMBOL

NAME AND FUNCTION

1, 2, 3, 4, 5,

6, 7, 15

QA to QH

Outputs

11

CCK

Counter Clock Input

12

CCKEN

Counter Clock Enable

Input

13

RCK

Register Clock Input

9RCO

Ripple Carry Output

14

G

Output Enable Input

10

CCLR

Counter Clear Input

8

GND

Ground (0V)

16

Positive Supply Voltage

INPUTS

OUTPUT

G

RCK

CCLR

CCKEN

CCK

H

X

X

X

X

Q OUTPUTS DISABLE

L

X

X

X

X

Q OUTPUTS ENABLE

X

X

X

X

COUNTER DATA IS STORED INTO REGISTER

X

X

X

X

REGISTER STAGE IS NOT CHANGED

X

X

L

X

X

COUNTER CLEAR

X

X

H

L

ADVANCE ONE COUNT

X

X

H

L

NO COUNT

X

X

H

H

X

NO COUNT