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b) Develop a circuit capable of processing signal 3. (Suggestion: See section 2.4.)
c) Draw an illustrative timing diagram for your circuit (as in i gure 8.28b), demonstrat-
ing that it indeed covers case 3.
Exercise 8.21: Synchronous Pulse Stretcher #2
This exercise concerns the synchronous version of a pulse stretcher whose behavior
was depicted in i gure 8.27c.
a) Present a state transition diagram for a Moore FSM capable of processing all three
signals (4 to 6). Should it operate at the positive or negative clock transition?
b) Draw an illustrative timing diagram for your FSM (as in i gure 8.28b), demonstrat-
ing that it indeed works as expected.
Exercise 8.22: Asynchronous Pulse Stretcher #1
This exercise concerns the asynchronous version of a pulse stretcher whose behavior
was depicted in i gure 8.27b.
a) Present a state transition diagram for a Mealy FSM capable of processing signals
1-2.
b) Draw an illustrative timing diagram for your FSM (as in i gure 8.28d), demonstrat-
ing that it indeed works as expected.
c) Develop a circuit capable of processing signal 3. (Suggestion: See section 2.4.)
Exercise 8.23: Asynchronous Pulse Stretcher #2
This exercise concerns the asynchronous version of a pulse stretcher whose behavior
was depicted in i gure 8.27c.
a) If the falling edge of signal 5 is beyond the falling edge of (async)
y
, will the solu-
tion presented in i gure 8.28c still produce the same result? If not, modify it to accom-
modate this situation as well.
b) Develop a circuit capable of processing signal 6. (Suggestion: See section 2.4.)
c) Draw an illustrative timing diagram for your circuit (as in i gure 8.28d), demonstrat-
ing that it indeed covers case 6.
Exercise 8.24: Eliminating Conditional-Timed Transitions
Because the conditional-timed transition (CD) in i gure 8.3 is the only transition that
departs from state C, it can be eliminated by splitting it into a simple timed transition
followed by a simple conditional transition.
a) Apply the principle described above to the FSM of i gure 8.3.
b) Can strategy #2 be now used to build the timer? Why couldn't it be used in the
original machine of i gure 8.3?
