**Assignment
No. 7 – Sequential Circuit Design**

1. A sequential circuit with two D flip-flops A and B, two inputs X and Y,
and one output Z is specified by the following input equations:

a. Draw the logic diagram of the circuit.

b. Derive the state table.

c. Derive the state diagram.

2. The sequential circuit shown below has two D flip-flops, one input X, and
one output Y. Derive the state table and state diagram of the circuit.

3. Design a sequential circuit with two D flip-flops A and B and one input
X. When X = 0, the state of the circuit
remains the same. When X = 1, the
circuit goes through the state transitions from 00 to 10 to 11 to 01, back to
00, and then repeats.

4. A Universal Serial Bus (USB) communication link requires a circuit that produces
the sequence 00000001. You are to design
a synchronous sequential circuit that starts producing this sequence for input
E = 1. Once the sequence starts, it
completes. If E = 1, during the last
output in the sequence, the sequence repeats.
Otherwise, if E = 0, the output remains constant at 1.

a. Draw the Moore state diagram for the circuit.

b. Find the state table and make a state assignment.

c. Design the circuit using D flip=flops and logic gates. An asynchronous set or reset should be
included to place the circuit in the appropriate initial state at which E is
examined to determine if the sequence of constant 1s is to be produced.