# Designing a sequential circuit

Discussion in 'Homework Help' started by ECESS, Nov 14, 2016.

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1. ### ECESSNew Member

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Any help on this problem would be very appreciated:

So I am supposed to solve a push button problem and draw the circuit, using any gates and multiplexers.

Design a sequential circuit which will output Z = 1 for exactly four clock cycles each time a person pushes a button ( which sets X=1) . Since clock is fast, X may still be 1 when the four Z=1 output have been generated. Therefore, after Z is 1 for four clock cycles, Z goes to 0, until X returns to 0 and then becomes 1 again.

So anyway I uploaded a photo of how far I got until I got stuck, I am not sure my state table is correct, any input would be appreciated.

Thanks

2. ### Les JonesWell-Known Member

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The problem is not sufficiently defined. How mny push buttons are there. How it the circuit supposed to behave if a button is pressed during the 4 clock cycles while Z=1 ?

Les.

3. ### specWell-Known MemberMost Helpful Member

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Isn't it funny- I could design a circuit to do this function in 5 minutes, but it's taking a while to follow the state tables.

spec

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5. ### RatchitWell-Known Member

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On the state graph, you have S5 defined to return to itself no matter if the push button is pressed or not. You also have S5 returning to S0 when the button is released. So which is it? It cannot be both. What is the problem or question with the state table? The top table appears to be OK, and the bottom table is not fully displayed.

Ratch