( ESNUG 285 Item 1 ) ----------------------------------------------- [4/3/98]
From: "Tom Harrington" <tharring@ford.com>
Subject: Design Compiler 98.02 "write_script" Writes Out Erroneous Code !
John,
We've been evaluating DC 98.02 here, and we've come across a problem
that may affect whether we can use this release.
Put simply: If you do a write_script in 98.02, you may get a script which
contains erroneous code. Reading this code back into dc_shell will then
cause errors. The worst offender we've seen so far is the following:
set_wire_load "SMALL" -library "udr180T155V45" -mode "enclosed" \
-selection_group "udr180T155V45" -library "udr180T155V45"
Astute readers will note that it's illegal to specify "-library" more
than once with a set_wire_load command, even if it's the same library.
If this is read back in to dc_shell, it correctly reports an Error.
This only seems to affect multi-pass compiles; it did not show up
in the first compile pass, but was present in subsequent passes.
We also saw several lines similar to the following:
set_input_delay 0 find(port,"MINS")
When read back in to dc_shell, you are of course warned not to specify
an input delay without an associated clock.
Synopsys has issued a STAR on this matter. So far I don't know of
a work-around.
- Tom Harrington
Ford Microelectronics
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