Re: Exact Timing Constraints vs. Over-Constraining

In article <[EMAIL PROTECTED]>, Allan Herriman wrote:
> On Tue, 2 Dec 2003 16:07:51 -0600, Richard Iachetta <[EMAIL PROTECTED]>
> wrote:
>>
>>Larry, your clocks must be pretty slow if you can afford to add 3 ns to every 
>>path in the design instead of just the few async boundary paths.  I would
>>call that majorly, not slightly, over-constraining the design.
> 
> Yes.  I have some 1.6ns clocks in my current design.  It would be a
> bit hard to make the constraint 3ns tighter.

"Everything is relative".  My current design needs to make 25 ns in
a XC2Sxxx-5.  I can afford to pad that by a few ns.

> Moral: avoid cookbook solutions.

It's worth knowing about cookbook solutions, using them properly when
they apply, _and_ understanding how to go beyond them when necessary.

     - Larry