CIS 600 1
Gates
• Gates are the building blocks for digital circuits
• Conventions used is high voltage = 1 and ground = 0
• Inverter and NOT Gate are two terms for the same circuit
• The following diagrams are logical and not physical circuit parts.
CIS 600 2
NOT Gate
0 1A X
A X
0 1
1 0
CIS 600 3
NOT Gate
1 0A X
A X
0 1
1 0
CIS 600 4
BUFFER
A X
0 0
1 1
A X0 0
Buffers are used to strengthen the signal and as a circuit delay. They can be made from 2 NOT Gates.
CIS 600 5
BUFFER
A X
0 0
1 1
A X
1 1
CIS 600 6
NAND Gate
A B X
0 0 1
0 1 1
1 0 1
1 1 0
A
B
X01
0
CIS 600 7
NAND Gate
A B X
0 0 1
0 1 1
1 0 1
1 1 0
A
B
X01
1
CIS 600 8
NAND Gate
A B X
0 0 1
0 1 1
1 0 1
1 1 0
A
B
X11
0
CIS 600 9
NAND Gate
A B X
0 0 1
0 1 1
1 0 1
1 1 0
A
B
X10
1
CIS 600 10
NOR Gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0
A
BX
0
01
CIS 600 11
NOR Gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0
A
BX
0
10
CIS 600 12
NOR Gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0
A
BX
1
00
CIS 600 13
NOR Gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0
A
BX
1
10
CIS 600 14
AND Gate
A B X
0 0 0
0 1 0
1 0 0
1 1 1
A
BX
00
0
CIS 600 15
AND Gate
A B X
0 0 0
0 1 0
1 0 0
1 1 1
A
BX0
01
CIS 600 16
AND Gate
A B X
0 0 0
0 1 0
1 0 0
1 1 1
A
BX
10
0
CIS 600 17
AND Gate
A B X
0 0 0
0 1 0
1 0 0
1 1 1
A
BX
11
1
CIS 600 18
OR Gate
A B X
0 0 0
0 1 1
1 0 1
1 1 1
00
0A
B
X
CIS 600 19
OR Gate
A B X
0 0 0
0 1 1
1 0 1
1 1 1
11
0A
B
X
CIS 600 20
OR Gate
A B X
0 0 0
0 1 1
1 0 1
1 1 1
10
1A
B
X
CIS 600 21
OR Gate
A B X
0 0 0
0 1 1
1 0 1
1 1 1
11
1A
B
X
CIS 600 22
Questions
• How to make AND gate from other components?
• How to make OR gate from other components?