CareerCup

1) The given circuit can be designed by the usual process of sequential circuit design.. To design without using reset we should add unconditional transitions from all the invalid states to a valid state such that after few clock periods the output states follow the desired order..

Please experts explain this question. I am not sure if I am right. Thank you.
1. It is johson counter. It needs four DFFs(D3, D2, D1, D0) and the Q' of D0 is connected to the D of D3. It does not need reset.
2. The first part is right shift registers and the second part is left shift registers. When Q3 is 1, it is right shift register. When Q0=1, it is left shift register.