MM54C90 National, MM54C90 Datasheet - Page 4

• Manufacturer Part Number: MM54C90
• Description: 4-Bit Decade / Binary Counter
• Manufacturer: National

Switching Time Waveforms
Truth Table
MM54C90 MM74C90 4-Bit Decade Counter
R
H
H
X
X
X
L
L
01
Output Q
BCD count
H
L
X
Reset Inputs
e
Count
e
e
R
Low Level
Irrelevant
Reset Count Function Table
High Level
0
1
2
3
4
5
6
7
8
9
H
H
X
X
X
L
L
02
A
BCD Count Sequence
is connected to Input B for
R
H
L
X
X
L
X
L
91
Q
H
H
L
L
L
L
L
L
L
L
D
R
H
X
L
L
X
L
X
92
Q
H
H
H
H
L
L
L
L
L
L
Output
C
Q
H
L
L
D
Q
H
H
H
H
Q
L
L
L
L
L
L
Output
B
L
L
L
Count
Count
Count
Count
C
Q
Q
L
L
L
H
H
H
H
H
L
L
L
L
L
B
A
Q
H
L
L
A
4
TL F 5889 – 7
MM54C93 MM74C93 4-Bit Binary Counter
R
H
X
L
01
Output Q
binary count sequence
H
L
X
Inputs
Reset
e
e
Count
e
10
11
12
13
14
15
Low Level
Reset Count Function Table
High Level
Irrelevant
0
1
2
3
4
5
6
7
8
9
R
Binary Count Sequence
A
H
X
L
02
is connected to input B for
Note 1 MM54C90 MM74C90 and MM54C93
MM74C93 are solid line waveforms Dashed line
waveforms are for MM54C90 MM74C90 only
Q
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
D
Q
L
D
Q
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
Output
C
Q
L
Output
C
Count
Count
Q
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
B
Q
L
B
Q
H
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
A
Q
L
A