( ESNUG 370 Item 14 ) ------------------------------------------- [05/17/01]
Subject: ( ESNUG 368 #9 ) Moody PrimeTime Runs Commands On Its Own Whim...
> Here is a quote from an engineer working with me:
>
> "The worst problem that I've come across so far is PrimeTime's inability
> to correctly implement false paths. For example, setting false paths
> between all asynchronous clock domains (as suggested by Synopsys) does
> not always work."
>
> And another:
>
> "Also use extreme caution with the 'reset_design' command, you can easily
> be resetting far more than you bargained for!"
>
> I observed this "ignoring false paths" problem in the early days with
> PrimeTime. The realy frustrating thing is that you do not get to find out
> the tool has (partially) ignored your command until you get the results
> from the next report. Why, oh why, does it not tell you it has ignored
> you? There seems to be no way to find out why either!
>
> - Dyson Wilkes
> Ericsson Microelectronics Europe
From: Tobias Thiel <tobias.thiel@motorola.com>
Hi, John,
In the recent weeks I also got very frustrated by PrimeTime when it was
either ignoring the set_case_analysis command or it was unwilling to reset
what was set with set_case_analysis.
As long as I was applying set_case_analysis to input ports everything is
working fine. But when I set it on internal pins, like the clock input of
an extracted model that is instanciated, it sometimes simply shows no
effect. And what is worse, in some cases I was able to set the case
analysis for a pin, but than I am unable to remove it! Even a
reset_design won't do the job, I had to unlink the design and re-link it!
Luckily my customer was not relying on the timing information generated
with the PrimeTime script that I provided. But since interface problems
like these are almost impossible to work around, he missed his deadline
and I was looking (or at least feeling) bad.
- Tobias Thiel
Motorola Germany
---- ---- ---- ---- ---- ---- ----
From: Fu Hui <hfu@ezmsgp.hl.siemens.de>
Hi John,
We have same problem for PT-2000.05-2. We change it back to PT-1999.10
and it works fine now.
- Hui Fu
Microcontroller ICs & DSP
Infineon Technologies Asia Pacific
|
|
