Question

QUESTION 1 The following dice roll FSM is operated at a frequency of 1MHz, and features a single with a single push-button input, b. Because human response time is much larger than the lus period of the system clock, any human press will result in b going high for a pseudo-random number of cycles. Since this FSM rapidly switches state when b=1, after the button is released the FSM will stop in a pseudo-random state. Side 1 Side 2 Side 3 d[2:0]=001 d[2:0]=010 d[2:0]=911 Side 6 Side 5 Side 4 b b b d[2:0]=110 d[2:0]=101 d[2:0]=100 Assume that setup and hold times are less than half of a clock period, and the clock-to-Q delay is negligible Assuming the button is connected directly to the controller's input b and the machine is initially in the state Side 1, fill in the timing diagram below:

Answer 1

1)

For the first three cycles b=0, so output stays at side 1.

Output d2d1d0=001

From 4th cycle, b=1.

So every cycle, output changes from

Side 1 to side 2 and then to side 3, side 4 , and so on

So

d2d1d0=010

d2d1d0 =011

And so on

From the given options,

Option C is correct

clk OOOOOOOOOOOOOOOOO b d2 do clk OOOOOOOOOOOOOO b d2 dn. do clk OOOOOOOOOOOOOO b d2 d1 do QUESTION 2 In order to give the highest chance of correct operation, which of the following are needed for input B? Before you select your answer, be sure to consider what constitutes correct operation for this machine None of the above Synchronizer Pulser and Synchronizer O Pulser

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2)

For the best operation of the circuit, input B has to satisfy both setup and hold conditions.

So B cannot change whenever it wants and has to be in synchronization with clock.

So we need to a synchronizer

Option B is correct