# Analyze sequential circuit

Discussion in 'Homework Help' started by mo2015mo, May 20, 2013.

1. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
Hi guys ,

I have been having problem with the attached question (fig 1), I have tried to solve it as attached figure 2,

Is this solution correct? IF Not ..why and what the correct solution..

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2. ### LDC3 Active Member

Apr 27, 2013
920
160
Since B0 is always 1, then you can remove every other row in your state table. Why have it in there if it is not needed. You should state that B0 is always 1 before the table so the professor will know why it is not included in the table.

Since Q = B1, whenever Q is different from B1 as in the 7th, 8th, 15th, and 16th state, what will happen? What should you say on the table?

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3. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
How different ?? Q = B1

I filled next state Q(t+1) by characteristic table for JK-flipflop

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4. ### LDC3 Active Member

Apr 27, 2013
920
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What I am saying is that since Q (an output) sets B1 (an input) to the same level, how can you have B1 as 0 when Q is forced to 1 since J is 1 ? What happens then ?

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5. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
it is toggling command

6. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
Really did not understand.. Please explain more

• ###### fig 31.jpg
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Last edited: May 20, 2013
7. ### LDC3 Active Member

Apr 27, 2013
920
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OK, now that we established that the output Q toggles, that is then written in the state table. Does the toggling effect any other outputs (A>B, A=B) ?

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8. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
yes , because B1 = Q and B0=1

9. ### LDC3 Active Member

Apr 27, 2013
920
160
Do the outputs toggle continuously, or does a steady state develop ? If it toggles for more than 10 cycles (depending on the number of states), I would probably say it was continuously.

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10. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
yes, the outputs toggle continuously
i have written all the probabilities of the output in the state table

Use Don't care ?

11. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
Where the wrong in the state table ?? J-k Column or Q(t+1) Column or external output??

12. ### LDC3 Active Member

Apr 27, 2013
920
160
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13. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
ok ,i.e. my solution (fig3) is correct

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14. ### LDC3 Active Member

Apr 27, 2013
920
160
yes, it's correct

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15. ### mo2015mo Thread Starter Member

May 9, 2013
157
1
LDC3

thanks you for help me