Honored ContributorI have seen two circuit for synchronizing Asynchronous signal as the following shows:
http://blogimg.chinaunix.net/blog/upfile2/080115160658.jpg Any different between them?
Honored ContributorYes, the first is to synchronise a nReset signal, it has an output also without an active clock, the second to synchronize general signals, the problem I discussed in my reply to your previous posting.
Honored ContributorWhy don't use the second circuit to synchronise a nReset signal?
Why don't use the first circuit to synchronise general signals?Honored ContributorThe top circuit is design to go into reset asynchronously but come out of reset synchronously. The bottom circuit goes into and out of reset synchronously. The top circuit is important to use in cases were a reset stops the clock.
Honored ContributorHonored ContributorHonored ContributorHello,
you can answer the question yourself, if you ask: Could there be a reason to have a reset working without a clock present? If you see a reason, then you should use the first circuit, if not, use the "general" synchronisation circuit, as you like. One possible reason can be, that reset should cause all outputs to switch to a safe state. Regards. Frank
