how to sync fast domain clock to slow domain clock domain

[luyuwang]

synchronizing two clock domains

Hi,everyone:
now I design a FIFO,I have encounter this problem:
I use writer pointer and read pointer to determine full or empty status.
now I supose write clock is faster than read clock(maybe many times),before comparing the two pointers,I need synchronize write pointer to read pointer,the question is how to synchronizer fast domain clock to slow domain clock domain(write poniter to read pointer)?
thanks
handshake?or other method?
thanks again!

 

[ramana459]

fast clock to slow clock

use clock divider circuit and give the divide clock signal to read

 

[cnz]

fast clock to slow clock signal sync

Maybe you can take slow clock as enable signal of fast clock, assume the two clock have the same phase