Transcript Digital Logic Design

Digital Logic & Design
Dr. Waseem Ikram
Lecture 06
Recap
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Logic Gates Basic Building Blocks
Symbol
Performs unique function
Represented by a function/truth table
Function expression
Timing Diagram
Recap
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AND Gate
F=A.B
OR Gate
F=A+B
NOT Gate
FA
AND Gate enables/disables device
OR Gate car door alarm system
NOT Gate 1’s complement
Recap
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Alternate Symbolic representations
NAND Gate
NOT-AND operation F  A  B
Universal NAND Gate
NOR Gate
NOT-OR operation F  A  B
Universal NOR Gate
NOR Universal Gate
Input
A
0
0
1
1
B
0
1
0
1
Output
F
0
1
1
1
1
2
NOR Universal Gate
Input
A
0
0
1
1
B
0
1
0
1
Output
F
0
0
0
1
1
3
2
NAND-NOR Universal Gate
1
1
3
2
4
3
2
4
NAND Gate Applications
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Device Failure Alarm
ALARM
NOR Gate Applications
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Washing Machine Controller
Switch
XOR Gate
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1 output
2 inputs
Multiple inputs
0
=1
0
0
XOR Gate function
Input
A
0
0
1
1
B
0
1
0
1
Output
F
0
1
1
0
F  A B
XOR Gate Timing Diagram
t0
t1
t2
t3
t4
t5
t6
XNOR Gate
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1 output
2 inputs
Multiple inputs
0
=
0
0
XNOR Gate function
Input
A
0
0
1
1
B
0
1
0
1
Output
F
1
0
0
1
F  A B
XNOR Gate Timing Diagram
t0
t1
t2
t3
t4
t5
t6
XOR Gate Applications
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Detecting odd number of 1’s
A
B
1
3
C
D
2
XNOR Gate Applications
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Detecting even number of 1’s
A
B
1
3
C
D
2
TTL/CMOS NOT Gate
+VCC
P-Type
MOSFET
Vo/p
+V
Vi/p
NPN
Transistor
+VDD
Vi/p
N-Type
MOSFET
Vo/p
Type of IC Logic Gates
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74XX00
74XX02
74XX04
74XX08
74XX10
74XX11
74XX20
Quad 2-input NAND Gate
Quad 2-input NOR Gate
Hex Inverter
Quad 2-input AND Gate
Triple 3-input NAND Gate
Triple 3-input AND Gate
Dual 4-input NAND Gate
Type of IC Logic Gates
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74XX21 Dual 2-input AND Gate
74XX27 Triple 3-input NOR Gate
74XX30 Single 8-input NAND Gate
74XX32 Quad 2-input OR Gate
74XX86 Quad 2-input XOR Gate
74XX133Single 13-input NAND Gate
Logic Gate Integrated Circuits
14
13
12
11
10
9
8
14
13
12
11
10
9
8
1
2
3
4
5
6
7
1
2
3
4
5
6
7
7432
Four 2-Input OR Gate
7408
Four 2-Input AND Gate
14
13
12
11
10
9
8
14
13
12
11
10
9
8
1
2
3
4
5
6
7
1
2
3
4
5
6
7
7404
Hex Inverters
7400
Four 2-Input NAND Gate
Logic Gate Integrated Circuits
14
13
12
11
10
9
8
1
2
3
4
5
6
7
7402
Four 2-Input NOR Gate
14
13
12
11
10
9
8
14
13
12
11
10
9
8
1
2
3
4
5
6
7
1
2
3
4
5
6
7
7486
Four 2-Input XOR Gate
74266
Four 2-Input XNOR Gate
Integrated Circuits (IC)
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CMOS Complementary Metal Oxide Logic
TTL Transistor-Transistor Logic
ECL Emitter Coupled Logic
PMOS p-channel MOS transistor
NMOS n-channel MOS transistor
E2CMOS
Operational Characteristics
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DC Supply Voltage
Noise Margin
Power Dissipation
Frequency Response
Fan Out