Computer Science Department, Bucknell University
CS320 Homework #2 Due Friday September 15, 1995

1. Draw the truth table for the following CMOS circuit.

2. Draw a CMOS circuit for a three input NOR gate.

3. Draw a CMOS circuit for A XOR B.

4. You are to determine how many flip flops can fit on a silicon chip with an area of 1 square inch.

Assume it takes six CMOS transistors to make a flipflop. The following is a top view of a CMOS transistor with the minimum size requirements indicated by a parameter called lambda.

Furthermore, there must be a minimal separation of 4lambda between transistors in both the x and y direction for electrical integrity and for wire connections.

a). How many flipflops if lambda = 1.5 microns ( a reasonable value for late 1980s)? Remember that

1 micron = 1 one-millionth of a meter.

b). How many flipflops if lambda = 1.0 microns ( a common value for 1995)?

c. How many flipflops if lambda = 0.5 microns ( a state-of-the-act value for 1995)?


Page maintained by Dan Hyde, hyde@bucknell.edu Last update September 25, 1995

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