Implement a combinational circuit that is capable of adding or subtracting two 8-bit signed 2s-complement binary numbers (A and B), producing an 8-bit signed 2s-complement binary result (R). In addition to the two 8-bit numbers, your circuit will accept a one-bit input signal M; if M = 0, your circuit should perform addition; otherwise your circuit should perform subtraction by adding the 2s-complement of the subtrahend to the minuend. Draw the diagram.

Overflow may occur when adding two binary numbers. You are required to add an overflow detection circuit to your binary adder/subtractor. This circuit should output a logical HI value whenever overflow occurs:

a) Add two positives and get a negative result: M A₇ B₇ R₇ = 0001.

b) Add two negatives and get a positive result: M A₇ B₇ R₇ = 0110.

c) Subtract a negative from a positive and get a negative result: M A₇ B₇ R₇ = 1011.

d) Subtract a positive from a negative and get a positive result: M A₇ B₇ R₇ = 1100.