CS 755 VLSI Systems Design

Spring 2002

Homework #1   Solution


Problem 1

                F = not((A.B) + (B.C) + (A.C))
 
 
 

 
 

Problem 2

               Logic diagram for Odd parity on eight input bits
 
 

 

             CMOS implementation of XNOR gate
 
 




Problem 3

              Truth table for 2 to 4 decoder
 

S1
S0
OUT
0
0
D0
0
1
D1
1
0
D2
1
1
D3

            From the truth table we get:

            D0  =  S0'.S1'  =  (S0 + S1)'

            D1  =  S0.S1'   =  (S0' + S1)'

            D2  =  S0'.S1   =  (S0 + S1')'

            D3  =  S0'.S1'  =  (S0'+ S1')'
 

      a)      Implementation using CMOS gates
 
 

 
 

     b)  Implementation using Transmission gates