RE: [SI-LIST] : IBIS Subcommittee Formed to Review Spice to IBIS

Beal, Weston (Weston.Beal@COMPAQ.com)
Mon, 7 Jun 1999 18:11:52 -0500

Kellee,

You're disagreeing a mute point. Your point was the same point I was trying
to state by saying, "the IBIS creator tool should have an algorithm to
remove points in linear regions." We should delete all these extra data
points. The problem that s2ibis has now is that all points are equal
difference. They should be closer in knee points and very sparse is linear
regions. The IBIS creator tool should have an algorithm to clean out extra
data.

So, I agree with you and now you can agree with me.

Later,
Weston Beal
Signal Integrity Engineer
Compaq Computer Corp.

-----Original Message-----
From: Kellee Crisafulli [mailto:kellee@hyperlynx.com]
Sent: Monday, 07 June, 1999 2:19 PM
To: Beal, Weston; ibis@eda.org
Subject: RE: [SI-LIST] : IBIS Subcommittee Formed to
Review Spice to IBIS

Hi

I have a comment on Weston's comment on the number of data
points.
I disagree on one point. Instead of increasing the number
of points generated
in the IBIS file the spice to IBIS tool should improve the
quality of the
points
choosen.

I can hand build files with 50 points that out perform files
with 400 points.
The big gain is that the FILE SIZE is reduced with higher
accuracy.
Large IBIS files will take up many megabytes on 1000's of
hard drives.
The V/I and V/T tables are the largest part of IBIS files.
Increasing them 4 x will generally increase the file size 3
x or more.

>The third thing that I changed was the number of points in
the time
>waveforms from 50 to 101. I have to remove one point to
comply with the
>golden parser, but I get better detail. On the issue of
number of points in
>a curve or waveform, I think the user should be able to
define any degree of
>granularity and the IBIS creator tool should have an
algorithm to remove
>points in linear regions. If the resulting curve still has
too many points,
>then increase the linearity tolerance and try it again.

Best wishes...
Kellee