Re: Connector spec swathing

Hi Chris, Chris,

I do like Chris Rokusek's idea of having the parser
create a full matrix. This is not part of the specification
but rather would be part of the parser's specification. It
would also create at least one unambiguous representation
of the matrix.

I do not agree that the method should be unambiguous however.
I do agree that the data must be unambiguous which I belive
it will be when we are finished. Mostly likely this is really
your concern.
The swath method is an approximate method.
All the connector companies I know of already uses this
method with the existing SPICE models; they just require
a manual operation by the user.
The IBIS swath method refines this more and allows it
to be automated for the first time. There are many methods possible
some that interpolate, some that compress, some that decompress,
and some that constrain to only the swath. These all depend
on the end goal and need for a given situation. So forcing
a particular type of conversation may lock out some uses of
the model.

best wishes
Kellee

At 01:29 PM 6/13/00 -0700, chris wrote:
>Hello,
>
>Chris is absolutely correct. We need an unamiguous method of
>building an arbitrary submatrix from the connector swath. At
>ICX we wrote a program that translates SPICE connector models
>into full matrix models which our tool can use. This is a
>difficult process and needs significant input from the user.
>There are many cases with ambiguities, sometimes without even
>one clearly right answer let alone the case where there might
>be more than one right answer.
>
>The problem is best illustrated by considering what the SI
>tool must accoomplish. Given a particular situation to simulate
>(which may include coupling to other nets) certain pins on each
>component must be included in the simulation. If any two (or
>more) of these pins are situated such that using the swath for
>both of them results in an overlapping set of pins (but not
>coincident) then what is the coupling matrix that should be used?
>
>Chris Reid
>
>
>Chris Rokusek wrote:
> >
> > Kellee & IBIS connector committee,
> >
> > The DAC IBIS meeting was one of the best I've attended...well done!
> >
> > I would like to request that the description of the "swath" matrix also
> > describe how to properly construct a fully-coupled matrix from the swath
> > matrix since there appears to be more than one "right" way to do it.
> >
> > It would also be nice if the parser itself could perform this algorithm so
> > that a simulator may (if it so desires) just query the full matrix
> > regardless of how it was specified (swath, full, sparse, ...).
> >
> > Best Regards,
> >
> > Chris Rokusek
> > Innoveda

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Have a great day....
Kellee Crisafulli
HyperLynx, a division of Pads Software Inc.
SI,EMC,X-talk and IBIS tools
E-mail: <mailto:kellee@hyperlynx.com>
web:   <http://www.hyperlynx.com>
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Received on Tue Jun 13 14:07:38 2000