## Answers to Selected Problems on Synchronous Sequential Logic

(See Chapter 6 of Mano's Digital Design (2nd ed.))

6-1 Construct a D flip-flop that has the same characteristics as the one shown in Fig. 6-5, but instead of using NAND gates, use NOR and AND gates.

6-2 Construct a D flip-flop that has the same characteristics as the one shown in Fig. 6-5, but instead of using NAND gaates, use NOR gates.

6-3 The D flip-flop shown in Fig. 6-5 can be constructed with only four NAND gates. Draw the modified circuit and show that it operates the same way as the original circuit.

6-17 Substitute binary assignment 2 of Table 6-8 to the states in Table 6-7 and obtain the binary state table. Repeat with assignment 3.

Trivial.

6-18 Analyze the circuit shown below and prove that it is equivalent to a T flip-flop.

Construct a truth table for D, with T and Q(t) as inputs. Then use the characteristic table of a D-type flip-flop to form the fourth column of this table for Q(t+1). Now if we discard the column headed by D, the resulting table is identical to the characteristic table of a T-type flip-flop. Thus the proof.

COSC 3410 Answers to Selected Problems, Chapter | 1 | 2 | 3 | 4 | 5 | 6 | 7 |