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From: Fredxx on 10 Aug 2010 08:15
I have a design with too many global clocks which ISE automatically adds.

Some of these clocks are slow and feed into relatively small areas of logic.

Is there a way I can specify these clocks to be non-global?


From: Benjamin Krill on 10 Aug 2010 08:22
Hi,

try to use BUFR.

cheers
ben

On Tue, 2010-08-10 at 13:15 +0100, Fredxx wrote:
> I have a design with too many global clocks which ISE automatically adds.
>
> Some of these clocks are slow and feed into relatively small areas of logic.
>
> Is there a way I can specify these clocks to be non-global?
>
>


From: Fredxx on 10 Aug 2010 08:34
Benjamin Krill wrote:
> On Tue, 2010-08-10 at 13:15 +0100, Fredxx wrote:
>> I have a design with too many global clocks which ISE automatically
>> adds.
>>
>> Some of these clocks are slow and feed into relatively small areas
>> of logic.
>>
>> Is there a way I can specify these clocks to be non-global?
>
> Hi,
>
> try to use BUFR.
>
> cheers
> ben
>

Many thanks. I thought all was going well until Translate. Unfortunately
Spartan 3A's don't support the BUFR primitive!


From: Benjamin Krill on 10 Aug 2010 08:38

> Many thanks. I thought all was going well until Translate. Unfortunately
> Spartan 3A's don't support the BUFR primitive!

Hm, to bad. Then you have to reduce your clocks and for example use clock
enables for the slower logic parts.


From: Chris Maryan on 10 Aug 2010 10:03
On Aug 10, 8:38 am, Benjamin Krill <b...(a)codiert.org> wrote:
> > Many thanks.  I thought all was going well until Translate.  Unfortunately
> > Spartan 3A's don't support the BUFR primitive!
>
> Hm, to bad. Then you have to reduce your clocks and for example use clock
> enables for the slower logic parts.

I'll second the clock enables. A common techinique is to use a single
clock for most of your logic and (through various mechanisms) generate
clock enables at the appropriate rate where necessary. This also makes
timing analysis much easier since everythign is carried on a single
clock.

Chris
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