synchronization - want to send the q of flop1 tp flop2

[anildesh]

synchronization

Hi All,

I have one flop working at 100MHz now i want to send the q of flop1 tp flop2 working at 10MHZ how should i synchronize I just have to send a pulse so i should not use FIFO.


Thanks,
Anil.

 

[viju]

synchronization

Hi Anildesh,
You can use two flop synchronizer to address your problem.
As you have mentioned that your source freq. is faster than your destination freq. , you must ensure that the faster pulse get sampled correctly in slower domain.
Now this two freq. you mentioned might not be in sync with each other. (i.e not from the same source). So you need to stretch the pulse and then send it to slower domain such that it get sampled correctly at slower domain.
You can do the pulse stretching by using T flip flop.
say you have a pulse in faster domain. Now you pass it through the tFF and then to 2 flop synchronizer. At the slower clk domain you have to keep on more FF + AND gate and inverted(posedge detector)to generate the pulse (from the level that was generated by the TFF @ faster clk domian).

Hope this helps...
I could have explained this with more clarity with figures...please let me know if you have any doubts...

 

[anildesh]

Re: synchronization

Hi Viju,

Thanks for your reply,but generally in a clock domain crossing the the data is sampled on a destination clock frequency. If u can give me a pictographic view it would be great.

u can send it to anildesh@gmail.com

Thanks In Advance,
Anil.

 

[ljxpjpjljx]

Re: synchronization

cross domian clock need to be checked using a lot of methods,it's very important!