Question 4: Sequential Logic Circuit Timing Diagram (7 points) The following circuit is called a Johnson counter. It has a number of uses in digital circuits. A n-bit Johnson counter requires n flip-flops to implement. The following Johnson counter is composed of 3 rising edge-triggered D flip-flops. Assume the outputs Q2,Q1 and Q0 of the D flip-flops are all 0 initially. Complete the timing diagram below for the outputs of this circuit. Note: ignore propagation delay