ise 5.2 sp 3 for spartan 3

[Anjan]

Hi
I have a design which takes about 74% resources on a sparta 3 1.5 m
device.
I am compiling on 5.2 sp3. The routing fails. In fact I tried lot of
things but no use. Has anybody encountered similar problem. Thanks
Rgd
Anjan

 

[Ray Andraka]

Have you tried increasing the effort level? If so, you might have to do
some floorplanning to improve the layout so that the routes don't get as
congested. As a last resort, you might also revisit the design to see
if you can re-architect it to have less global routing. The spartan3
and virtex2 parts really have quite an abundance of routing, so this
type of problem is much less common than it was with the 4K and earlier
families. Probably the most frequent causes of no route are: 1) use of
too many tbufs on a common bus line. These are relatively scarce and
require the tbufs to locate in the same row and in specific columns in
order to keep from eating up routing resources and killing performance.
The placer does a lousy job of placing the tbufs, so you'll probably get
much better results placing them by hand. 2) routing in/out of BRAM and
multipliers going to multiple places. These tend to congest the
routjng, and again, the placer does not do the greates job with these,
so they may be located away from the rleated logic and need routing
running across other dense areas.

Anjan wrote:

Hi
I have a design which takes about 74% resources on a sparta 3 1.5 m
device.
I am compiling on 5.2 sp3. The routing fails. In fact I tried lot of
things but no use. Has anybody encountered similar problem. Thanks
Rgd
Anjan

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--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email ray@andraka.com
http://www.andraka.com

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