Re: Rising Waveform Loading Effects

Chris Rokusek, Quad Deisgn Technology wrote:
>
>There are a few "dimensions" of knowledge not explicity present in the
>.ibs model which may be useful to a simulator:

That is precisely my point. You are making certain assumptions and guesses,
which are OUTSIDE the ibis specification. In fact you are trying to guess
the information which ibis is trying to hide. What do you do if you encounter
some data which does not fit any of your guesses?

All the knowledge "dimensions" should be utilized in developing the specification,
but once the specification is developed, it should have any loose ends.

Let us assume that you have a simulator which can predict waveforms for any
arbitrary load, given ONE waveform for one RESISTIVE load. But the ibis
specification does not specify that. A model developer can specify a waveform
into a general RLC load (as shown in the example on page 19 of 2.1 specification)
and claim that they have provided a perfectly legal ibis model and now it is
up to the simulator to do the rest. What does
the simulator do in this case with the waveform with all the ringing, overshoot,
undershoot etc.? The simulator should not place restrictions in ADDITION to
the ibis specification. Therefore, if one waveform into one resistive load
is all that is required, then it should be stated explicitly. Otherwise
different people can make different assumptions and guesses. If certain things
are REQUIRED to carry out a simulation, then the ibis model should SPECIFY
those things instead of leaving them to guesswork.
------------------------------------------------------------
Dileep Divekar
Applied Simulation Technology, Inc.
2188 Bering Drive
San Jose, CA 95131

Phone - (408)-434-0967 x 100
Fax - (408)-434-1003
Email - dileep@apsimtech.com
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Received on Wed Oct 30 08:53:35 1996