RE: [IBIS-Users] Simulation with VT tables for different load conditions

From: Muranyi, Arpad <Arpad_Muranyi@mentor.com>
Date: Thu Sep 16 2010 - 21:45:10 PDT

Bob,

Thanks for the note on this. This seems to be a pretty
clever way of doing the extraction, and fairly simple
too (as long as the *_fixture circuit remains simple
and can be solved like that).

But we need to be careful with our selection of words.
This presentation talks about extraction, and calculates
the I_die(t) in the presence of the known LRC *_fixture
elements during extraction. And this is the correct
answer to the original question which dealt with
*_fixture.

My presentation, on the other hand, deals with the
reactive loading problem of an I-V / V-t curve based
IBIS model during simulation. This problem cannot be
solved with the Synopsys presentation you quoted if the
basic IBIS algorithm only uses the 2EQ/2UK algorithm,
because it involves only Ohm's law and doesn't have
enough information for the EDA tool to solve the
differential equations associated with the reactive
loads.

So strictly speaking I have to admit that I didn't
answer the original question by quoting my own
presentation, but the two topics are related.

Arpad
========================================================

-----Original Message-----
From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On
Behalf Of Bob Ross
Sent: Thursday, September 16, 2010 1:52 PM
Cc: ibis-users@eda.org
Subject: Re: [IBIS-Users] Simulation with VT tables for different load
conditions

Hi Sunrendra:

Even though IBIS has syntax to support reactive load elements
(L_fixture, C_fixture, and even L_dut and C_dut) we recommend
not extracting models using these elements. Some tools do not
even support these load elements, and others may support them
by vendor-specfic methods.

However, it is possible to process reactive loads by
accounting for the time-varying reactive path derivatives
within the four V-T methodology. One presentation provides
some details.

   http://www.eda.org/ibis/summits/sep07a/chen.pdf

Bob

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.
--------------------------------------------------------------------
|For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org
|with the appropriate command message(s) in the body:
|
|  help
|  subscribe   ibis       <optional e-mail address, if different>
|  subscribe   ibis-users <optional e-mail address, if different>
|  unsubscribe ibis       <optional e-mail address, if different>
|  unsubscribe ibis-users <optional e-mail address, if different>
|
|or e-mail a request to ibis-request@eda-stds.org.
|
|IBIS reflector archives exist under:
|
|  http://www.eda-stds.org/pub/ibis/email_archive/ Recent
|  http://www.eda-stds.org/pub/ibis/users_archive/ Recent
|  http://www.eda-stds.org/pub/ibis/email/         E-mail since 1993
Received on Thu Sep 16 21:45:31 2010

This archive was generated by hypermail 2.1.8 : Thu Sep 16 2010 - 21:46:16 PDT