( ESNUG 427 Item 3 ) -------------------------------------------- [04/14/04]

From: David Bishop <david.bishop=user  domain=kodak spot calm>
Subject: This Magic Switch Gets PrimeTime To Report Unconstrained Paths

Hi, John,

Now that PrimeTime is a separate release from Design Compiler, I have been
busy creating "sub installs" for PrimeTime in my Synopsys directories.  You
still need to do this as not all versions of PrimeTime work with all
versions of DC.

One problem that cropped up recently was when a user was checking his
clock-to-output times and started getting a blank report.  PrimeTime simply
did not report any paths from the clock to the output!  Come to find out
that the user didn't constrain that path, and the newer versions of
PrimeTime just don't report on unconstrained nets.

I quickly came to the conclusion that this was a bad thing.

A quick call to Synopsys turned up the magic switch, which is:

             set timing_report_unconstrained_paths true

Which I now set in my default .synopsys_pt.setup files.

    - David Bishop
      Kodak                                      Rochester, NY