::: 4. For the parallel adder in the Figure, determine the complete sum by analysis of the logical operation of the circuit. Verify your result by longhand addition of the two input numbers. 34 A B C танск 7. The circuit shown in the Figure is a 4-bit circuit that can add or subtract numbers in a form used in computers (positive numbers in true form; negative numbers in complement form). a) Explain what happens when the Add /Subt. input is HIGH. b) What happens when Add /Subt. is LOW? Add/Subs O- ABC C ABC ABC 2 Σ Σ

Fig: 1