What is the problem?

mbarazeen said:

ericgibbs, the OP needed to have a divide by 2 counter by looping the out put to the input, where he struggled.

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mindhacker said:

Example is this. I connect its Q' to its D input. Q is supposed to be 0 then 1 then 0....but it works indefinitely. As if it is in undefined state What causes this? How can I fix it?

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mbarazeen said:

OP in his post#1 stated...


Indirectly he wanted to make a divide by 2 counter. i suggested to try the one i posted in #11. i don't know which one he said not working..

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ericgibbs said:

hi,
This is what I get with your circuit, I hope I have copied it correctly.

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mbarazeen said:

for every clock pulse there must be a state change...but in the simulation it takes few clocks, i doubt the caps playing a role?

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ericgibbs said:

hi,
If I remove the 'dta input source' , this what I see in simulation.
The 100pF caps are to enable the simulator to give a solution.

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mbarazeen said:

of cause it has to be tested without data input source, it seem you have removed the feed back from Q' too?. try if you have a step by step simulation to see how data changes with eevry clock pulse raising & lowering.

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ericgibbs said:

hi,
I dont see any feed back on your circuit from Q, the simulation circuit is the same as your post.?? #11

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mbarazeen said:

on your post #23 its shown correctly, q2 & data are connected (feed back), i meant the same.

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