Digital Sequential Circuit

Ergh said:

Hello, I am confused on how to go about answering the question. The resources such as youtube, and google have proved inadequate, hence why I'm here. I hope someone with a better understanding of digital may be able to get me going on a systematic approcach on answering the following question, and future ones:

https://i60.tinypic.com/hsp0ty.png

Thanks in advance guys, it's really appreciated.

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Ratchit said:

You make a table of states with columns labeled Ja,Ka,Qa,Qa(t+1) ... Jc,Kc,Qc,Qc(t+1). You have 3 gates, so that makes 8 different states. Fill in the rows for each state. Start with Qa = Qb = Qc = 0 . Then you can determine what the J and K inputs are for each state and determine what the value of Q(t+1) is for the next state. Transfer the Q(t+1) value to the Q of the next row and continue from there.

For this circuit, the sequence is 0->4->6->3->1->0 . If you start from 2, then the sequence is 2->5->7->6->3->and continues with the previous sequence.

Ratch

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Ergh said:

Thanks Ratch for replying. Actually I am more confused now. Would there not be 16 states A,B,C, and an input (x)?

Thanks.

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Ratchit said:

Where is the input X on the schematic? The number of states is 2^3 = 8.

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Ergh said:

Sorry, I am letting the clock equal x. which would give 4 inputs. 2^4 = 16.

Thanks.

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