3. Design a sequential circuit with two flip-flops A and B and two inputs E and X. If E=0, the circuit remains in the same state, regardless of the value of X. When E=1 and X=1, the circuit goes through the state transitions from 00 to 01 to 10 to 11 , back to 00 , and then repeats. When E=1 and X=0, the circuit goes through the state transitions from 00 to 11 to 10 to 01 , back to 00 , and then repeats. Design the circuit using the following types of FFs: (i) Positive-edge-triggered DFF. (ii) Positive-edge-triggered JK-FF. (iii) Positive-edge-triggered T-FF