# Help!! How to make State diagram out of the following circuit?

#### Yoheena

Joined Aug 24, 2020
6
Hi
I’m quite new to learning about digital technology, so please I need help in understanding how to create a state diagram for the following circuit, I have tried multiple ways but I can’t figure how to go there when I have both a D flip-flop and a JK-flip-flop at the same time. Im studying for an exam and I need help with figuring this out fast!

pls Help!

#### ericgibbs

Joined Jan 29, 2010
16,383
hi Y,
Welcome to AAC.
As this is Homework we need to see your attempt at answering the question, we can then help.
E

#### Yoheena

Joined Aug 24, 2020
6
hi Y,
Welcome to AAC.
As this is Homework we need to see your attempt at answering the question, we can then help.
E
hi Y,
Welcome to AAC.
As this is Homework we need to see your attempt at answering the question, we can then help.
E
Hi

here is my following answer, and then I don’t know how to continue. as for this problem that I am trying to solve, it’s actually an problem from an older test, and I am right now going through it, because my final exam is tomorro, so I am not cheating so u know =D.
so please show me how its done because tomorrow I might encounter a similar problem, and I really don’t know how Go from an circut to a state diagram or even the other way, because our teacher didn’t give us problems to solve before the test with the answer to them, he said we would do fine.

so here I am trying to figure it out without succes.

#### Yoheena

Joined Aug 24, 2020
6
How to get a next state table from the circuit abow? That’s all I need help with.

best regards Yoheena

#### WBahn

Joined Mar 31, 2012
27,406
Pick some combination for the current state, say Qa=1, Qb=0, Qc=1. What are the J,K inputs to each of the flip flops? What will the outputs of all the flip flops be after the next rising clock edge?
Do that for all possible states.

Frankly, if you can't do a problem like this in your sleep very early in the course, you are not in any shape to be taking the final exam (or passing the course).

#### Yoheena

Joined Aug 24, 2020
6
But what about the D flip flop? Do i Ignore It An just consider the jk flip flops? And from the jk derive a next state table. Right?

#### Yoheena

Joined Aug 24, 2020
6
By the the way can u pls go through it like in this video, so I can understand pls if u don’t mind.

pls help me solve the problem while I am awake though ;D

#### ci139

Joined Jul 11, 2016
1,873

#### Yoheena

Joined Aug 24, 2020
6
Thanks for the image, but how do I make a next state table from that like this blue table below ex.

#### ci139

Joined Jul 11, 2016
1,873
? maybe

#### WBahn

Joined Mar 31, 2012
27,406
But what about the D flip flop? Do i Ignore It An just consider the jk flip flops? And from the jk derive a next state table. Right?
You do the same thing. For each possible set of the values for the three FFs, what is the input to the D FF and what is the next output?

#### WBahn

Joined Mar 31, 2012
27,406
By the the way can u pls go through it like in this video, so I can understand pls if u don’t mind.

pls help me solve the problem while I am awake though ;D
After watching the video, what is it that is keeping you from solving this problem?