( ESNUG 342 Item 1 ) --------------------------------------------- [2/03/00]

Subject: ( ESNUG 340 #1 )  We Found PKS Timing Correlates Within 3 Percent

> A final note: in it's current state PKS uses Ambit at the front end with
> the Ambit Static Timing Analyzer, and Qplace at the back end with Pearl
> as the Static Timing Analyzer, something we thought was a mishmash and
> certain to cause timing correlation problems.
>
>     - Jon Stahl, Principal Engineer
>       Avici Systems                             N. Billerica, MA


From: Jay McDougal <jaym@hpcvcdt.cv.hp.com>

Hi John,

I have to disagree.  We use both Ambit and Silicon Ensemble (Qplace).  I
have also been using PKS for about 4 months and have found that the timing 
correlation between Ambit, PKS, Pearl, and even PrimeTime is very good.
Sure there will be some 1-2% differences but I consider that noise.  I am
getting great timing closure within 0-3% of PKS predicted timing after
full routing and parasitic extraction.  I call that great!  Now, if I could
just get better correlation between the PKS "router" and the final Wroute
to agree on congestion and routability I would really be happy.  I have to
agree that a single timing engine is preferable, but I find actual use of
the current solution very workable and better than Jon Stahl's "mishmash"
characterization that was given here. 

    - Jay McDougal
      Agilent Technologies (formerly Hewlett-Packard)