CS 140L Lecture 1 Professor CK Cheng 3/31/02

CMOS Logic (3.2 – 3.6) Complementary Metal-Oxide Semiconductor

1. Transistors (FET) Field Effect Transistor G S D NMOS D WG S D L G =1 => D =S { D = 1 => S = 0.8 D = 0 => S = 0 G = 0 => D&S are separated.

G C D S r L W, c WxL A C ’ C B G S D PMOS G = 0 => D =S { D = 1 => S = 1 D = 0 => S = 0.2 G = 1 => D&S are separated.

2. Transmission Gate A C C BC = 0 => A&B are separated. C = 1 => A = B

3. Inverter AB A = 1 => B = 0 A = 0 => B = 1 Thus B = A

4. NAND gate B A A B A B Z Z = D iff AB = 1. Z = (AB)’ Z

5. NOR gate B A A B A B Z Z = 1 iff A+B = 0. Z = (AB)’ = (A+B)’ Z

6. XOR gate B A Z B’ A’ B A B’ A’ Z = ab’ + a’b = a + b

7. Multiplexer d1 d2 S S S ‘ Z If S=1, Z = d1 Else (S=0), Z = d0 Z = S d1 + S’ d0

Basic Boolean Algebra a + a = 1 a * a = a = 1 1*a = 1 a + a = a a * a = a a a

DeMorgan’s Law (a + b)’ = a’ * b’ (a*b)’ = a’ + b’ ab