MadeEasy Test Series: Digital Logic - Digital Counter

Question

The modulus value of the below asynchronous counter is __________.

Comments

AB config is in 6th cycle.I suspect you are doing positive edge triggering. I got 0-1-2-3-4-5 and then it clears

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Can u tell me the sequnce of by table coz I m geting 0-1-2-3-0.

Answer 1

It is an asynchronous counter. 

it goes from $0 , 1 , 2 ...$ so on till it get cleared and returned to $0$ again. 

It will return to $0$/Clear when NAND will produce $0$.

That will happen at A and B both are $1$, i.e, ABC at $110$. 

But state $110$ will not be counted

we have previous state $101$, 

then 

 $\underbrace{1}^{\text{A}}_{\text{this is old 1 }}\quad \underbrace{0}^{\text{B}}_{\text{Change to 1}}\quad \underbrace{1}^{\text{C}}_{\text{Change to 0}}$

Actually $110$ is not result in states, and counter get cleared (with new B as 1, and Old A as 1). 

We get states as $0,1,2,3,4,5,0,1,....$

MOD$6$ Counter.

Comments

Sir, why $110$ should not be included it is not clear to me. I think it should be included because as soon as $A$ and $B$ set to $1$, then $NAND$ clear all flip flop to $0$ in the $8^{th}$ clock cycle.

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sir ,how you decided that  A is MSB and not C?

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@mitesh kumar  C is LSB bit because external clock apply on C( T-FF)....