I finally made simple 4-bit synchronous counter and somehow its start from 3 as well, but I have no idea how to solve completely. I know how to do with asynchronous counter but this synchronous now. I insert my basic 4-bit synchronous counter.

 

hi Sedus,
Welcome to AAC.
Is this a simulation or hardware project.?

What drives U6-5 input.?
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Simulation, U6-5 is simple high state.

 

Hi,
So you do not apply a Low going Clear signal.??

Is this a simulation or hardware project.?

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Simulation project.
No I dont.

 

So how do you know that the Counter will be set to All Clear when powered On.?

 

Honestly, I dont understand, its counting 0-15 repeatedly, should I use low signal to all clear?

 

hi,
In an actual circuit a Clear pulse would be applied, usually at power up.
This ensures all Counter are in the cleared state before applying the count input pulses.

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This is one option.
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I finally made simple 4-bit synchronous counter and somehow its start from 3 as well, but I have no idea how to solve completely.

You've shown us a standard binary counter. How do you expect it to count from 3-12?

 

You've shown us a standard binary counter. How do you expect it to count from 3-12?

Using gates?

 

Using gates?

Post the work you did to design the counter.

 

Well, I gave up xd Bye

 

Well, I gave up xd Bye

You won't go far with that attitude.

Designing synchronous counters is straightforward. I do these homework problems for fun.

 

Good for you. I tried to figure out the whole thing but I didn't get any further, I understand how synchronous counters works but thats it, I can still trying with this preset and clear thing but I dont know what am I exactly doing. I can easily do asynchronous counter which is counting 3 to 12, but this...

 

I tried to figure out the whole thing but I didn't get any further

If you post your work, we can see what method you're using and where you're having problems.

I understand how synchronous counters works but thats it, I can still trying with this preset and clear thing but I dont know what am I exactly doing.

Synchronous counters don't rely on preset or clear.

The counter you were asked to design isn't very complicated. I only needed the 4 flip flops and half a dozen gates.

 

So, I used AND gate which is connected to 1,4 and 8 Q output so it should switch at 12, and the other side of gate I connected to 1 and 2 P input so it should be start at 3, it works but the problem is when the counter switch from 7 to 8 for something the gate's input value was 15 instead of 8, somehow 1,2 and 4 output is delayed a little bit before going low when switch to 8. So I made a 3-7 synchronous counter by mistake. I cant fix this, so here I am, I tried, I would appreciate some real help or guidance about I'm on the right track or completely wrong?

 

I would appreciate some real help or guidance about I'm on the right track or completely wrong?

Textual descriptions of circuits is a non-starter for most of us. If you're serious about getting help, post a schematic and show your work.

 

this is

 

this is

so U7 got all 3 input to high when counter switching 7 to 8.