RE: Package Parasitics

Hello,

It's also possible to have pin specific parasitics which override the Package specific parasitics.

| ----- Cut from the IBIS 2.1 specification -----
[Pin] signal_name model_name R_pin L_pin C_pin
|
  1 RAS0# Buffer1 200.0m 5.0nH 2.0pF
  2 RAS1# Buffer2 209.0m NA 2.5pF
| ------------------------------------------------

Regards
Dave

David Makihara
Manager, System Interface Modelling
PMC-Sierra Inc.
105-8555 Baxter Place
Burnaby, BC V5A 4V7
tel:604-415-6000 ext 2422
fax:604-415-6206
e-mail:makihara@pmc-sierra.bc.ca
website: http://www.pmc-sierra.com

> -----Original Message-----
> From: Kim Helliwell [mailto:khelliwe@acuson.com]
> Sent: Tuesday, April 24, 2001 2:46 PM
> To: Jay Azurin
> Cc: ibis-users@eda.org
> Subject: Re: Package Parasitics
>
>
> Jay Azurin wrote:
> >
> > Hello,
> >
> > I am new to the IBIS game so pardon my simplistic question.
> I would like
> > to know the meaning of the values in an IBIS model:
> >
> > [Package]
> >
> > |variable typ min max
> >
> > R_pkg 250m 200m 300m
> >
> > L_pkg 8nH 5nH 12nH
> >
> > C_pkg 0.7pF 0.56pF 1.2pF
> > |
> >
> > I have found other models that have these values set to zero:
> >
> >
> > > > > [Package]
> > > > > R_pkg 0 0 0
> > > > > L_pkg 0 0 0
> > > > > C_pkg 0 0 0
> >
> > Can you explain why these values are used, i.e. why the
> model would be
> > realistic with no package parasitics?
> >
> > Thanks for your help.
> >
> > Best regards,
> > Jay Azurin
> > Motorola NetComm Applications
>
> The package parasitics might be included in the pullup,
> pulldown, and clamp
> curves in some way. While this is permissible (I think), it
> makes it much
> harder to re-use the pullup/pulldown/clamp curves for any
> other package. The
> whole point of separating these effects is to allow re-use of
> the curves with
> different package models.
> --
> Kim Helliwell
> Senior CAE Engineer
> Acuson Corporation
> Phone: 650 694 5030 FAX: 650 943 7260
>
 
Received on Tue Apr 24 16:16:00 2001