CSC270 Exercises on FSM

--D. Thiebaut 15:24, 28 February 2011 (EST)

---

Exercise #1

• Implement a sequencer (FSM) which activates 3 Lights: a green light, a yellow light, and a red light. The behavior of the FSM is the following:
  • the green light stays on for 30 seconds, then
  • the yellow light comes on and stays on for 30 seconds, then
  • the red light comes on and stays on for 30 seconds, then we repeat the pattern.
  • There is only one light on at a given time.
• What is the frequency of your clock signal?

         +---------+  	      	       +--------
         |         |		       |
  G -----+         +-------------------+
                   +---------+
                   |         |
  Y ---------------+         +-----------------
                             +---------+
                             |         |
  R -------------------------+         +-------

Exercise #2

• Same as Exercise 1, but this time the behavior is the following
  • the green light comes on after the red light and stays on for 30 seconds,
  • the yellow light comes on and stays on for the next for 15 seconds,
  • the red light comes on after the yellow light for 30 seconds.
• What is the frequency of your clock signal?

Exercise #3

• Create a "true" frequency divider that divides by 4.

Exercise #4

• What is the state diagram of the 3-flip-flop circuit with the following equations:

     D0 = Q0'
     D1 = Q0 XOR Q1
     D2 = Q1 XOR Q2

Exercise #5

• Same question, but solve it with Python.
• You may find the Python Logic Operators Example Page useful for this exercise.

Exercise #6

• What is the state diagram of this FSM?
  • D1= Q0
  • D0 = ( Q0 ^ Q1 )'

• What happens when the flip-flops start in the state where Q0 and Q1 are both 1?

...