
SN54/74LS168 • SN54/74LS169
SN54/ 74LS168
UP / DOWN DECADE COUNTER
STATE DIAGRAMS
SN54 / 74LS169
0
1
2
3
4
0
1
2
3
4
15
5
15
5
14
6
Count Up
Count Down
14
6
13
7
13
7
12
11
10
9
8
SN54 / 74LS168
UP:
TC = Q0 ⋅ Q3 ⋅ (U / D)
DOWN: TC = Q0 ⋅ Q1 ⋅ Q2 ⋅ Q3 ⋅ (U / D)
12
11
10
9
8
SN54 / 74LS169
UP:
TC = Q0 ⋅ Q1 ⋅ Q2 ⋅ Q3 ⋅ (U / D)
DOWN: TC = Q0 ⋅ Q1 ⋅ Q2 ⋅ Q3 ⋅ (U / D)
LOGIC DIAGRAMS
SN54 / 74LS168
P0
P1
P2
P3
PE
CEP
CET
U/D
TC
CP
CP D
Q0
Q1
Q2
Q3
FAST AND LS TTL DATA
5-2