Design a two bit counter circuit that counts from 0 to 2 only, that is, it will have states 00, 01, 10 only. The initial state of the counter may be assumed to be 00. The counter will be in following successive states: 00, 01, 10, 00, 01, 10, 00, 01, 10, 00 ... Use any flip flop to design the circuit. You must design them using state transition diagram and Karnaugh's map.

Q:-      Design a two-bit counter circuit that counts from 0 to 2 only, that is, it will have states 00, 01,             10 only. The initial state of the counter may be assumed to be 00. The counter will be in following successive states: 00, 01, 10, 00, 01, 10, 00, 01, 10, 00 ... Use any flip-flop to design the circuit. You must design them using state transition diagram and Karnaugh's map?

answer:-

There are 2 flip-flop inputs for counter i.e. A, B. The next state of the flip-flop is given in the table.

DA indicates the flip-flop input corresponding to flip-flop-A. This counter requires 2-flip-flops. 

Thus, the simplified input equations for BCD counter are:

The logic circuit can be made with 2 D flip-flops, 2 OR gates & 4 AND gates.