hd74ls191 Renesas Electronics Corporation., hd74ls191 Datasheet - Page 6

• Manufacturer Part Number: hd74ls191
• Description: Synchronous Up / Down 4-bit Binary Counter Single Clock Line
• Manufacturer: Renesas Electronics Corporation.

HD74LS191
Count Sequences
Illustrated below is the following sequence:
Rev.2.00, Feb.18.2005, page 6 of 10
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.
Enable G
Down/Up
Max/Min
Ripple
Clock
Clock
Load
Q
Q
Q
Q
C
D
A
B
C
D
A
B
Load
13
14
Count Up
15
0
1
2
Inhibit
2
1
0
Count Down
15
14
13