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-   -   ChipScope 8.1i. Timing has got worse? (http://www.fpgacentral.com/group/showthread.php?t=58543)

Symon 05-04-2006 04:10 PM

ChipScope 8.1i. Timing has got worse?
 
Hi All,
I've started using ISE8.1. SP3 has been available awhile, and the angry
posts about 8.1 on this newsgroup dropped enough for me to upgrade.
Anyway, my new angry post is this. I think the new version of Chipscope,
8.1.03i seems to have worse timing than previous versions. When I have a
wide capture buffer, say 80 ish, the thing won't place and route at 150MHz.
This used to work fine. Also, all my own designs that were close to the
timing limit before upgrading have similar if not identical timing, so it's
not due to a timing file upgrade.

I wonder if some bright spark in the Chipscope project has reduced the
amount of pipelining to save on the amount of real estate? If so, they've
buggered the performance when the thing has a wide capture bus.

Anyone else had similar experiences?

Cheers, Syms

p.s. I'm using V2PRO parts.



Symon 05-04-2006 04:45 PM

Re: ChipScope 8.1i. Timing has got worse?
 
"Symon" <[email protected]> wrote in message
news:[email protected]
> Anyway, my new angry post is this. I think the new version of Chipscope,
> 8.1.03i seems to have worse timing than previous versions. When I have a
> wide capture buffer, say 80 ish, the thing won't place and route at
> 150MHz.

Update: It seems that Chipscope has gone back to changing the names of nets
so that the UCF contraints don't work.

More soon....



Symon 05-04-2006 05:07 PM

Re: ChipScope 8.1i. Timing has got worse?
 
"Symon" <[email protected]> wrote in message
news:[email protected]
> "Symon" <[email protected]> wrote in message
> news:[email protected]
>> Anyway, my new angry post is this. I think the new version of Chipscope,
>> 8.1.03i seems to have worse timing than previous versions. When I have a
>> wide capture buffer, say 80 ish, the thing won't place and route at
>> 150MHz.

> Update: It seems that Chipscope has gone back to changing the names of
> nets so that the UCF contraints don't work.
>
> More soon....

Yeah, my UCF was expecting a net called fast_enable. Sadly it failed to
notice Chipscope had changed the name to "ila0_trig0<56>".
Grrrrr...
Syms.




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