Lecture 1: Introduction to Digital Logic Design

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Lecture 1 Introduction toDigital Logic Design

• CK Cheng
• Thursday 9/26/02

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We will cover four major things in this
course- Combinational Logic- Sequential
Networks- Standard Modules- System Design
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Overall Picture of CS140
input
Memory
conditions
Pointer
Mux
Control Subsystem
ALU
control
Memory
conditions
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Two Types of Circuits
x1 . . . xn
xi
fi(x)
CLK
Combinational logic
Sequential Networks 1) Memory 2) Time Steps
(Clock)
yi fi(x1,..xn)
yit fi (x1t,xnt, s1t, snt) Sit1
gi(x1t,,xnt, s1t,.snt)
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Part I. Combinational Logic
ab
a b
ab cd
e (abcd)
c d
cd
e

• I) Specification
• II) Implementation
• III) Different Types of Gates

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Review of Boolean algebra and switching functions
AND, OR, NOT
AND
OR
NOT
A B C 0 0 0 0
1 0 1 0 0 1 1 1
A B C 0 0 0 0
1 1 1 0 1 1 1 1
A C 0 1 1
0
A 1
A 1
A
1
A 0
A 0
A
0
1 dominates in OR
0 dominates in AND
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1. Identity A 1 A A 1 1 A 0
0 A 0 0
2. Complement A A 1 A A 0
3. Distributive Law A(BC) AB AC
ABC (AB)(AC)
A B
A
B C
A C
A B
A
B C
A C
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5. Associative (AB) C A (BC)
(AB)C A(BC)
C
A
A B
B C
C
A
A B
B C
6. Demorgans Law (AB) AB (AB) A
B
7. AC AB BC AC BC