74HC590_2

© NXP B.V. 2009. All rights reserved.

Product data sheet

Rev. 02 — 28 April 2009

5 of 21

NXP Semiconductors

74HC590

8-bit binary counter with output register; 3-state

6.

Functional description

[1]

H = HIGH voltage level;

L = LOW voltage level;

X = don’t care;

↑ = LOW-to-HIGH transition;

↓ = HIGH-to-LOW transition.

[2]

RCO = Q0’ · Q1’ · Q2’ · Q3’ · Q4’ · Q5’ · Q6’ · Q7’ (Q0’ to Q7’ are internal outputs of the counter).

Table 3.

Function table[1] [2]

Inputs

Description

OE

CPR

MRC

CE

CPC

H

X

X

X

X

Q outputs disable

L

X

X

X

X

Q outputs enable

X

↑

X

X

X

counter data stored into register

X

↓

X

X

X

register stage is not changed

X

X

L

X

X

counter clear

XXH

L

↑

advance one count

XXH

L

↓

no count

X

X

H

H

X

no count