Weber Chuang(ChingFu Chuang)
SI Engineer, System Team.
VIA Technologies, Inc.
Taipei, Taiwan, ROC
Very Innovative Architecture
******************** Re: [SI-LIST] : IBIS Modeling
> At 11:22 AM 3/24/98 -0700, D. C. Sessions wrote:
> >In brief, the answer is that IBIS device models are *not* good
> >You absolutely need to model the substrate and the terminators (DIMM
> >series resistors) on them. IBIS 3.1 includes the capability of
> >defining Electrical Board Descriptions, which are basically
> >netlists of the PWB. The examples given are in fact memory modules.
> >D. C. Sessions
> We have built DIMM and SIMM module modules using IBIS 2.1 that do
> a reasonable simulation job. It requires a bit of playing with the
> package model and it is somewhat simulator dependant. Our simulator
> large RLC package values as transmission lines instead of lumped LC
> which allows us to make a reasonable DIMM or SIMM module module using
> IBIS 2.1 To accomplish this we create a full circuit boad model of the
> DIMM or SIMM and then tweak an IBIS package model until it looks
> the same under several simulation conditions. The die model input
> must also be increased to account for the extra loading.
> While I agree IBIS 3.x makes this relatively easy and provides a more
> result it is possible to get usable results with 2.1 prior to the
> release of
> the 3.x parser.