1. Design a 3-bit up-down counter with a control input P such that when P it counts up and when P it counts down.

2. Analyze the synchronous circuit shown below:

<br><br> <img src='./qimages/8871-2.jpg'> Write down the excitation and output functions. Form the excitation table and state table.

3. Design a modulo-8 counter which counts in the way given below. Use JK flip-flops in your realization. <img src='./qimages/8871-3.jpg'>

4. The output z of a fundamental-mode two-input sequential circuit is to change from 0 to 1 only when x2 changes from 0 to while x1= 1. The output is to change from 1 to 0 only when X1 changes from 1 to while X2 1. Find a minimum row reduced flow table. Write a set of hazard-free excitation and output equations.

5. A sequential circuit has two pulse inputs x1 and x2. The output of the circuit becomes when one or more consecutive x1 pulses are followed by two x2 pulses. The output then remains for all subsequent x2 pulses until all x pulses occur. Derive a minimal state table. Synthesize the circuit using set-reset flip-flops.

6. Explain the design of hazard-free combinational circuit and the design of hazard-free asynchronous circuit.

7. What are the different types of hazards? Explain how these can be avoided.

8. Explain the synthesis of symmetric functions with the help of a suitable example.

9. Write short notes on any two of the following: Generation of Spikes Relay Contents Conversion of Mealy Circuit to Moore Circuit