Exercise 8.18 (Complete Circuit Design of the Extended Control for a Road Work Traffic Light). Design the sequential circuit of an extended control for a road work traffic light and verify the result of the synthesis. Use the same method as applied in the previous exercises. The behavioral model is given in Fig. 8.3 b), and the result of Exercise 8.2, and the associated graph in Fig. 8.4. Practical tasks:

1 Load the TVL system e8102.sdt of Exercise 8.2. This TVL system includes the system function F(x, s, sf , y) of the given non-deterministic finite-state machine as object number 1.

2 It is known from Exercise 8.10 that this finite-state machine is not realizable.

Extend the finite-state machine such that from each state not used so far any of the used states is allowed to be reached and for security reasons of the traffic light all output functions must be 0 which means the controlled lights are off. Solve this task by appropriate XBOOLE operations.

3 Verify whether the completed finite-state machine of the extended control for a road work traffic light is realizable.

4 Calculate all required controlling functions using DV -flip-flops. Calculate additionally the output functions and the resulting global list of phases.

Check the correctness of each calculated memory and output function immediately.

5 Verify whether the designed sequential circuit realizes the required behavior.

6 Draw the graph of the realized finite-state machine of an extended control for a road work traffic light and compare it with the given behavior of Fig. 8.4.