Ff regarding question .

Question

If there is sequential synchronous circuit and it is producing following distinct stages

0->2->1->4

Then how many ff is needed to draw it ?

Comments

3....

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why?

Answer 1

The states are 0-2-1-4.

so if we take 2 flipflops states produced are 0,1,2,3

hence 4 is not there .to represent the fourth state we need 3 bits.

Hence 3 flip flops are enough to represent  the states 0,1,2,3,4,5,6,7

out of which our counter is 0-2-1-4.

Comments

is there any formula or shortcut to find answer of such questions??

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So you want to say that we should see largest produced value and

make it 2^n>= largest value ,n is # of FF . Right?

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Now your formula is true even when n=2 and largest value=4 .(u are saying that from 2 flip flops u can make states 0,1,2,3,4) and it cannot be possible.

Just think that ,to represent the state 4 u need 3 bits . one flip flop is capable of holding 1 bit so 3 flip flops needed.