Sequential Logic Design: Controllers

Controller Design

Three-cycles-high laser timer controller

• Read Section Control Block Design of [1, p136];

• Read Example 3.7 of [1, p 136-7];

• Implement the circuit of Fig. 3.50 of [1, p137] following the steps descibed in Clip 1 using Logisim; and

• Evaluate the circuit operation.

Activities

1. Using Logisim, implement the circuit for the Button press synchronizer of Example 3.9 of {1, p139-40] and evaluate its operation (use scope);

2. Using Logisim, implement the circuit for the Sequence generator of Example 3.10 of {1, p140-1] and evaluate its operation (use scope);

3. Using Logisim, implement the circuit for the Secure car key controller of Example 3.11 of {1, p141-2] and evaluate its operation (use scope).

Converting a Circuit to an FSM (Reverse Engineering)

• Read Example 3.12 of [1, p142-3];

• Using Logisim, implement the circuit of Fig. 1 that corresponds to the combinarional logic of Fig. 3-59;

• After implementing, obtain the true-table selecting  Project / Analise Circuit / Table in Logisim;

• Compare the true-table obtained in Logisim with Table 3.6 of [1, p143].

• Finally, draw the FSM diagram following the steps of Fig. 3.60 of [1, 143].

Activities

1. Obtain the FSM diagram of Exercice 3.46 of [1, p164].

State reduction

State minimization

• Read Section State Reduction of [1, p335-9];

• Regarding  Fig. 6.35 of [1], Fig. 2 shows the original FSM;

• Fig. 3 show the steps of the Algorithm for State Reduction of Table 6.2 of [1] ;

• In Fig. 4 are shown the information after checking the next states for each input value and the reduced FSM. 

Activities

1. Read Example 6.13 of {1, p339];

2. Solve Exercise 6.16 of [1] .

State Encoding

Alternative Minimum-Bitwidth Binary Encodings

• Read Section Alternative Minimum-Bitwidth Binary Encodings of [1, p342];

• Read Example 6.14 of [1, p343] and compare the Fig 6.42 of the book with Fig. 5 below;

• Follow the next steps for Controller Design Process of Table 3.2 {1, p136]. 

One-Hot Encoding

• Read Section One-Hot Encoding  of [1, p343];

• Read Example 6.15 of [1, p343] and compare the Fig 6.43 of the book with Fig. 6 below;

• Follow the next steps for Controller Design Process of Table 3.2 {1, p136]. 

Output Encoding

• Read Section Output Encoding  of [1, p345];

• Read Example 6.17 of [1, p345] and compare the Fig 6.47 of the book with Fig. 7 below;

• Follow the next steps for Controller Design Process of Table 3.2 {1, p136]. 

Activities

• Using Logisim, implement the circuit of Example 6.15 of [1, p342] and evaluate its operation;

• Using Logisim, implement the circuit of Example 6.16 of [1, p342-3] and evaluate its operation;

• Using Logisim, implement the circuit of Example 6.17 of [1, p344-5] and evaluate its operation;

• Using Logisim, implement the circuit of Example 6.18 of [1, p345-6] and evaluate its operation;

• Solve Exercises 6.19-6.21 of [1, p390].

Moore versus Mealy FSMs

• Read Section Moore versus Mealy FSMs od [1, p346-9];

• Compare Fig. 6.50 and Fig. 6.51 with Fig.  8 below.

Activities

1. Using Logisim, implement the circuits of FSMs Moore and Mealy  for the soda dispenser machine of Fig. 6.50 of [1, p348]

Bibliography and Resources

Bibliography

[1] Vahid, Frank; Sistemas digitais: projeto, otimização e HDLs 

• Library ID: 621.382:004 V127s

• Digital library: 9788577802371 

External Online Resources

• Frank Vahid Publications