$[50pts$ total$]$ Consider the ALU discussed in lecture $($schematic and control table given

below$).$

a$)[20$ pts$]$ Expand the ALU to include the XNOR and NOR functions. Show your

modified schematic and truth table.

b$)[30$ pts$]$ Add an output to the ALU called V $($Overflow$).$ V should assert when $2\text{'}$s

complement overflow has occurred in either subtraction or addition. It should

assert when any other operation $($AND$,$ OR$,$ XNOR, or NOR$)$ is being selected. Show

any equations and$/$or truth tables and show your modified schematic $($modified from

part $($a$)).$

Hints: Remember that overflow occurs when two operands of the same sign are added

and the result is the opposite. You will need to slightly adjust this for subtraction.