a. Draw the circuit diagram of a 4-bit binary adder-subtractorusing a 4-bit binary adder and XOR gates. Treat the adder asa block component with appropriate inputs and outputs. you doNOT need to show the internal gates of the adder.
b. two 4-bit unsigned binary numbers A3A2A1A0 and B3B2B1B0 can becompared by computing A-B. Develop bunary expressions for theoutputs Equal (A=B). Greater (A>B) and Less(A
hint: you must carefullt consider the C out and S3S2S1S0 outputsfrom the 4-bit binary adder-subtractor from part a . for example,what does C out =0 tell me about A-B? as an example to develop yourlogic, try peforming (0101)2-(0110)2 using 2s complement.
c. implement your magnitude comparator circuit using the4-bit binary adder-subtractor from part a some 2-input NORgates and some 2-input NAND gates: in your sketch only treat the4-bit binary addder as a block component (so repeat the sketch frompart a)