How to run a block with half the clockspeed on virtex 5

Mar 26, 2008 1 Replies
S

Hi!



I have the problem that a core (cordic) can't run with the desired clock (200MHz). As this specific core is totally uncritical for the performance of the system I want to run it with only half of the clock (100MHz).



I'm going to use a DCM to divide the clock by 2, and drive the cordic with the halfed clock. I got some problems with hold time violations when going from the lo- speed clock domain to the hi-speed clock domain.



Is there any application note / design example availiable that describes how to do this ?


Vote
Twitter Facebook LinkedIn
S

Thank You.

I'm currently trying to implement the design using a parallel cordic (which is able to reach 200MHz), but is of course a huge ressource waste. (this cordic will process 1 vector every 3000 clock cycles)

I'll try aour suggestion once I'm done with the current run, but a question remains:

will ISE be smart enough to notice that the cordic runs at half of the clock speed ? I have the feeling that ISE will still create timing violations in the cordic. Do I need to use timing groups?

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required