Assignment 16 (Assigned October 8)


1. Suppose you are given as a basic building block the 1-bit comparator discussed in the class. This comparator has two 1-bit inputs (A and B ) and three 1-bit outputs (AEQBout, AGTBout and ALTBout) with the following meanings:

ALTBout = 1 if A is less than B, 0 otherwise
AEQBout = 1 if A eqi\uals B, 0 otherwise
AGTBout = 1 if A is greater than B, 0 otherwise

This comparator has three 1-bit inputs ( AEQBin, AGTBin and ALTBin) with the meanings:

ALTBin = 1 if a higher-order compare found the A-bit less than theB-bit
AEQBin = 1 if a higher-order compare found the A-bit equal to the B-bit
AGTBin = 1 if a higher-order compare found the A-bit greater than the B-bit

Use your 1-bit comparator basic building blocks to design a 4-bit comparator that will compare two 4-bit unsigned integers, be sure to include in your answer the values you will assign to the leftmost AEQBin, ALTBin, and AGTBin inputs.

2. Take an example of two 4-bit numbers and show all the corresponding values on the 4-bit comparator circuit designed in Problem 1. Also show the final result.

3. Give the logic equations for the 1-bit comparator of problem 1.