Design a sequential circuit with two D flip-flops A and B, and one input x. When x = 0, the state of the circuit remains the same. When x = 1, the circuit goes through the state transitions from 00 to 01, to 11, to 10, back to 00, and repeats. Follow the steps below to design the circuit:
a. Draw the State diagram
b. From the state diagram, derived the circuit excitation and output/state table
c. Use K-maps to derive the necessary logic equations for the flip-flop inputs
d. Draw the sequential circuit.