Re: BIRD 6.1

>
> Hello IBIS members:
>
> Here is an updated BIRD6.1 to reflect the discussed and emailed changes.
> I would appreciate any comments or corrections from Kellee, Syed, Bob Ward,
> Jon, and anyone else as to whether this version meets the simulator needs
> and also contains information that is easily available from data sheets and
> from vendors. I am particularly concerned that "tskew_min" is meaningful.
> I am also concerned whether the normal test setup for tskew in data books
> which include 50pF/100pF loads gives overly pessimistic values. If you wish,
> you can reach me at (503) 684-6641, fax (503) 639-3469 or send email.

Regarding your statement:
"I am also concerned whether the normal test setup for tskew in data books
 which include 50pF/100pF loads gives overly pessimistic values."

If data book numbers are copied into IBIS models without verifying
simulation vs. time-domain measurements, then the data book capacitance
numbers could lead to faulty simulations. Faulty simulations, even if they
do provide conservative results, are a nuisance. We don't like finding out
that we have spent labor fixing problems that didn't really exist.

We rank models based on our confidence in them & models created from data
book info have the lowest ranking. The same driver with 2 different
package models can have very different waveforms. If an IBIS model uses
data book info, the model should have a disclaimer to say so.

-- 
Bob Canright		Convex Computer Corp.	Richardson, Texas
214-497-4474 (desk)	canright@convex.com	214-497-4500 (FAX)
disclaimer:
It's not my typing, the Sun keyboard repeeeatsss.