( ESNUG 240 Item 4 ) ---------------------------------------------- [5/9/96]
From: rainer@mucsun.sps.mot.com (Rainer Makowitz)
Subject: Backannotated Data Isn't Used By The Synopsys Floorplan Manager?
Hi John,
There was some brief coverage of Floorplan Manager in ESNUG earlier -- I hope
to get some comments on how to 'reoptimize_design' inside a hierarchy.
My problem: I read in cluster files (PDEF) and 'set load' scripts and select
a custom wire load model. When I do 'report_timing' from the *top level*
of the hierarchical design I get indication about the clusters in the report
and negative slack time. Yet when I do 'report_timing' *inside* a big module
that I want to reoptimize (the whole design takes days) there is no
indication that the report is using any backannotated information leaving
my slack time is positive!!?? (Likewise, 'reoptimize_design' on the sublevel
finishes without doing much. I have the feeling that the backannotated data
is not considered on any level other than the top level.) Has anybody out
there in ESNUG land have any idea how this works?
- Rainer Makowitz
Motorola Embedded Systems Group
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