School of Computer and Communication
Engineering, UniMAP
DKT 122/3 - DIGITAL SYSTEM I
Chapter 3: Logic Gates
Mohd ridzuan mohd nor
[email protected]
019-3806067
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3.0 LOGIC GATES
• Inverter (Gate Not)
• AND Gate
• OR Gate
• NAND Gate
• NOR Gate
• Exclusive-OR and Exclusive-NOR
• Fixed-function logic: IC Gates
 Three basic logic gates
 AND Gate – expressed by “ . “
 OR Gates – expressed by “ + “ sign (not an ordinary addition)
 NOT Gate – expressed by “ ‘ “ or “¯”
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School of Computer and Communication
Engineering, UniMAP

NOT Gate (Inverter)
a) Gate Symbol & Boolean Equation
b) Truth Table (Jadual Kebenaran)
c) Timing Diagram (Rajah Pemasaan)
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School of Computer and Communication
Engineering, UniMAP

OR Gate
a) Gate Symbol & Boolean Equation
b) Truth Table (Jadual Kebenaran)
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c) Timing Diagram (Rajah Pemasaan)
School of Computer and Communication
Engineering, UniMAP

AND Gate
a) Gate Symbol & Boolean Equation
b) Truth Table (Jadual Kebenaran)
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c) Timing Diagram (Rajah Pemasaan)
School of Computer and Communication
Engineering, UniMAP

NAND Gate
a) Gate Symbol, Boolean Equation
& Truth Table
b) Timing Diagram
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School of Computer and Communication
Engineering, UniMAP
NOR Gate


a) Gate Symbol, Boolean Equation
& Truth Table
b) Timing Diagram
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School of Computer and Communication
Engineering, UniMAP

Exclusive-OR Gate
a) Gate Symbol, Boolean Equation
& Truth Table
A  B  AB  AB
b) Timing Diagram
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School of Computer and Communication
Engineering, UniMAP
Examples : Logic Gates IC
NOT gate
AND gate
Note : x is referring to family/technology (eg : AS/ALS/HCT/AC etc.)
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School of Computer and Communication
Engineering, UniMAP
Q&A
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School of Computer and Communication
Engineering, UniMAP