HD74HC190, HD74HC191

Rev.3.00, Jan 31, 2006 page 4 of 12

Timing Chart

HD74HC191

Illustrated below is the following sequence:

1. Load (preset) to binary thirteen.

2. Count up to fourteen, fifteen (maximum), zero, one and two.

3. Inhibit

4. Count down to one, zero (minimum), fifteen, fourteen and thirteen.

Load

A

Data

Inputs

B

C

D

Clock

Down/Up

Enable G

Max/Min

Ripple

Clock

13

Load

14

15

0

1

2

2

1

0

15

14 13

Count Up

Inhibit

Count Down