3.11 Consider the circuit in Figure P3.1. Can this circuit be used as one stage in a ripple-carry adder? Discuss the pros and cons. The operation of transistors shown in the figure is described in Appendix B.
*3.12 Determine the number of gates needed to implement an n-bit carry-lookahead adder, as- suming no fan-in constraints. Use AND, OR, and XOR gates with any number of inputs.
*3.13 Determine the number of gates needed to implement an eight-bit carry-lookahead adder assuming that the maximum fan-in for the gates is four.