Repeat 4.5.1, but now design a circuit that accomplishes this operation 2 bits at a time.

Problem 4.5.1

Design a circuit with 1-bit data inputs and a 1-bit data output that accomplishes this operation serially, starting with the least-significant bit. In a serial implementation, the circuit is processing input operands bit by bit, generating output bits one by one. For example, a serial AND circuit is simply an AND gate; in cycle N we give it the Nth bit from each of the operands and we get the Nth bit of the result. In addition to data inputs, the circuit has a Clk (clock) input and a "Start" input that is set to 1 only in the very first cycle of the operation. In your design, you can use D Flip-Flops and NOT, AND, OR, and XOR gates.

The goal of this exercise is to help you familiarize yourself with the design and operation of sequential logical circuits. Problems in this exercise refer to this ALU operation:

a. Add (X+Y) b. Subtract-one (X-1) in 2's complement ALU Operation