Digital Design_ Principles and Practices, Chegg Solution Manual_parte_340

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Step 1 of 4 7.049E Refer to the excitation equations in the page number 566. D3=A Consider that the present states as and inputs as Obtain the inputs to the D flip-flops using excitation equations. =0 D3=0 For there are 3 flipflops, so total that is 8 combnations are to be checked. Using the excitation equations in the box on page 566, the transition list can be built as shown in Table 1. Table 1 Q3Q2Q1 AB Z 00 01 10 11 000 100 100 101 101 0 001 110 110 101 101 0 010 100 110 101 111 1 011 110 110 101 111 1 100 100 100 111 111 0 101 100 100 111 111 0 110 100 110 111 111 1 111 100 110 111 111 1 D1.D2.D3 Step of 4 Consider each input combination is considered as one state and as there are 8 input combinations, so total 8 states are available. The states are from S₀ to The full 8-state table is obtained using transition list in Table 1 and is as shown in Table2. Table 2 Q3Q2Q1 AB Z 00 01 10 11 S0 S4 S4 S5 S5 0 U1 S6 S6 S5 S5 0 U2 S4 S6 S5 S7 1 U3 S6 S6 S5 S7 1 S4 S4 S4 S7 S7 0 S5 S4 S4 S7 S7 0 S6 S4 S6 S7 S7 1 S7 S4 S6 S7 S7 1 D1.D2.D3 Step of 4 The state diagram is drawn using state table in the Table 2 and is as shown in Figure 1. AB A A'B A S7 A'B S6 A'B A' AB U2 A U1 U3 A'B' A'B' A AB AB' S4 S5 A A' A' A Figure 1 Step 4 of 4 U1, U2 and U3 are the unused states in the Figure 1. Figure 1 shows all the 8 states. Thus, the state diagram is drawn.