( ESNUG 368 Item 7 ) --------------------------------------------- [04/12/01]
Subject: ( ESNUG 364 #3 ) ACS 2000.5 Mem Leak Sort Of Fixed In 2000.11-SP1
> A few months ago we tried ACS on a real design. The ACS process ran out
> of memory while generating the constraints for the second phase (pass 1)
> compile. The Design Budgeter has a memory leak bug. Synopsys identified
> a workaround, but that only works in 2000.5. There's no fix for 2000.11.
> We're trying to get Synopsys to commit to a fix but it's hard going.
>
> - Tom Fairbairn
> 3Com Europe Ltd. Hemel Hempstead, UK.
From: Tom Fairbairn <tomf@pdd.3com.com>
Hi John,
After a few customers and Synopsys employees following up on my problem, I
thought I'd keep you up-to-date with my ACS troubles. I have a workaround
that seems to work (fixes the memory leak I had in acs_refine_design) with
version 2000.11-SP1. This is good as it gives us some confidence that it
will work in future versions. Synopsys is promising that I shouldn't need
the workaround and to expect great things from the next version after
2000.11 - but then EDA vendors always do that.
There is a slight problem, though. The workaround is to use a custom budget
script (/scripts/pass/budget.scr), that must say:
allocate_budgets -levels 2 -create_context
What this does is tells the budgeter to only create budgets 2 levels of
hierarchy down from the top. This solves the memory problem, but it
obviously means that you can't create a partition at any greater than 2
levels down in your hierarchy. Not a great problem for me (yet) but it is
a worrying little restriction.
Thanks for all your help, and keep on truckin'
- Tom Fairbairn
3Com Europe Ltd. Hemel Hempstead, UK.
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