( ESNUG 450 Item 6 ) --------------------------------------------- [01/25/06]
From: Daniel Lima Ferrao <dlferrao=usr domain=inf.ufrgs.br>
Subject: How to force PrimeTime to produce a Multiple-Input Change Vector?
Hi John,
I have found some strange behaviour with the "True-delay Input Vector"
generated by the report_timing -true option in PrimeTime (Ver W-2004.12).
When applying the vector reported with the set_case_analysis command, that
vector can't sensitize the critical path reported as true, and another path
is reported (with smaller delay).
The problem is that the vector reported is a "single-input change" vector.
Actually I've never got a vector that have multiple-input changes.
So the -true algorithm uses a vector to sensitize that is different from
the vector reported? The vector reported is like this one:
True-delay Input Vector
-------------------------------------------
a[0] (in) 1
a[1] (in) 1
b[0] (in) f
b[1] (in) 0
cin (in) 1
So I gotta a script that produces this commands:
set_case_analysis 0 a[0]
set_case_analysis 0 a[1]
set_case_analysis 1 b[0]
set_case_analysis 1 b[1]
set_case_analysis fall cin
But this vector can't sensitize the path reported, to do so the right vector
must be:
set_case_analysis fall a[0]
set_case_analysis fall a[1]
set_case_analysis 0 b[0]
set_case_analysis 0 b[1]
set_case_analysis fall cin
That is a multiple-input change vector.
Is there a way to force PrimeTime to produce a multiple-input change vector
or are only single-input change vectors supported??
- Daniel Lima Ferrao
UFRGS Rio Grande Do Sul, Brazil
Index
Next->Item
|
|
