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.