[SOLVED] 4 bit counter using J-K flipflop doubts

[Barasha]

Hello all,

Designing a up counter with JK FlipFlop, where do we connect the clear and preset pins.please help

 

[jeffrey samuel]

What IC's you are using Do post it

Cause some have inverted pins in the clr and preset pins And so you need to invert the input you are to give to them

 

[Barasha]

What IC's you are using Do post it

Cause some have inverted pins in the clr and preset pins And so you need to invert the input you are to give to them

Hi jeffrey samuel,
It is 7476 IC

 

[jeffrey samuel]

Then give inverted inputs to the corresponding pins

You need to give "High" If you don't want them to be triggered and "Low when both pins have to do their work

So if you are up counting then have this pin always at "HIGH" during the count process other wise they will reset the counts every clock and you will get garbage output

Hope this helps

 

[Barasha]

Then give inverted inputs to the corresponding pins

You need to give "High" If you don't want them to be triggered and "Low when both pins have to do their work

So if you are up counting then have this pin always at "HIGH" during the count process other wise they will reset the counts every clock and you will get garbage output

Hope this helps

Hi jeffrey samuel,
I gave a HIGH to both of them but the counting is not as it should be.I have a doubt.Do we need to clear first and then input HIGH to both of them.

 

[jeffrey samuel]

Hi jeffrey samuel,
I gave a HIGH to both of them but the counting is not as it should be.I have a doubt.Do we need to clear first and then input HIGH to both of them.

Yes Friend as initially some sort of Data can be present in the FF so it is better to clear the IC's before we do any fresh operation

 

[sequel]

also try debouncing your keys if they are of the mechanical type so that u dont end up giving multiple pulses at a go...cos this will certainly give you false results!

 

[Barasha]

Yes Friend as initially some sort of Data can be present in the FF so it is better to clear the IC's before we do any fresh operation

Thanks. Clearing before starting a new sequence is probably better.

- - - Updated - - -

also try debouncing your keys if they are of the mechanical type so that u dont end up giving multiple pulses at a go...cos this will certainly give you false results!

Hi sequel,
I will try that.Thanks

 

[jeffrey samuel]

also try debouncing your keys if they are of the mechanical type so that u dont end up giving multiple pulses at a go...cos this will certainly give you false results!

The exact word to be used here is not faulty counting

If an additional clock is given at the same time the step wise transtion may not be noticed by us due to very fast change of states

 

[sequel]

The exact word to be used here is not faulty counting

If an additional clock is given at the same time the step wise transtion may not be noticed by us due to very fast change of states

when dealing with mechanical switches it's very important to debounce it....dats a fact in the field of electronics. nevertheless if it is purely that of a microprocessor "controller" based system we cud ofcos make use of a software loop for the delay. lemme ask a question: if a need my jk flip flop to give or just as u say a make a transition of one with just a mechanical switch wot do u tink or feel the state of the flip flop wud luk lyk?....hmmm i guess it will not be defined "indeterminate logic!". except we make use of a one shot at the input with respect to wot i hav said.....quote me if am wrong.........
sequel!

 

[jeffrey samuel]

when dealing with mechanical switches it's very important to debounce it....dats a fact in the field of electronics. nevertheless if it is purely that of a microprocessor "controller" based system we cud ofcos make use of a software loop for the delay. lemme ask a question: if a need my jk flip flop to give or just as u say a make a transition of one with just a mechanical switch wot do u tink or feel the state of the flip flop wud luk lyk?....hmmm i guess it will not be defined "indeterminate logic!". except we make use of a one shot at the input with respect to wot i hav said.....quote me if am wrong.........
sequel!

Can you first repost here abiding the rules of the forum I am not able to get you

PS: SMS language is not allowed here

 

[Barasha]

Hi Jeffrey Samuel n sequel,

Reading the sequence was difficult before when i didn't clear the flip flops.It is working fine now.Thanks.