Q- Design the ripple counter whose output sequence is represented by the following state diagram.

Ans: As it is a 3-bit counter hence we firstly arrange 3 FFs and now we design the combinational circuit to reset the counter at appropriate point.
Q2 Q1 Q0 OUTPUT
0 0 0 0
0 0 1 1
0 1 0 1
0 1 1 1
1 0 0 1
1 0 1 1
1 1 0 1
1 1 1 0
And using K-map we get the combinational circuit as:
And the equation we get is
Z= Q2. (Q1 bar) + Q0. (Q1bar)
+ Q1. (Q0bar)
= Q2. (Q1 bar) + XOR (Q1, Q0)

OR
We can also have the equation as
Z= Q0. (Q1 bar) + Q1. (Q2bar)
+ Q2. (Q0bar)

And hence can have two types of combinational circuits to achieve the above counter. And the whole circuit with first combinational circuit as: