Subject: Re: [IBIS-Users] ibis model problem
From: Kevin Fisher (kfisher@sisoft.com)
Date: Wed Aug 21 2002 - 06:53:15 PDT
akhilesh.chandra@st.com wrote:
> Hi all,
>
> I got one warning in my IBIS model Can any one tell me why it is?
>
> WARNING - Model 'cell': TYP VI curves cannot drive through Vmeas=1.4V
> given load Rref=1e+06 Ohms to Vref=1.65V
>
> Cell is a simple bidirectional.
>
> I am unable to undersatnd what is the significance of this warning &
> how I can remove it.
>
> Regards
> Akhilesh
> |------------------------------------------------------------------
> |For help or to subscribe/unsubscribe, email majordomo@eda.org
> |with just 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 email a written request to ibis-request@eda.org.
> |
> |IBIS reflector archives exist under:
> |
> | http://www.eda.org/pub/ibis/email_archive/ Recent
> | http://www.eda.org/pub/ibis/users_archive/ Recent
> | http://www.eda.org/pub/ibis/email/ E-mail since 1993
Akhilesh,
One of the things IBISchk verifies is an IO/Output cell can drive the
timing reference load specified in the IBIS model (which in the case of
your cell is a 1Meg resistor to 1.65V) through the standard load
reference voltage (1.4V in this case). It does this by drawing a load
line representing the standard load on the IV table and checks that
Vmeas is within the range is between voltages where the the load line
crosses the low-state DC curve and the high-state DC curve.
However, there is not enough information above to diagose the problem.
It could be one of a number of things. If you could make the suspect
IBIS model available, it would make it much easier to figure out what's
going on here.
Thanks,
Kevin
-- Kevin M. Fisher Consultant Signal Integrity Software Inc. 6 Clock Tower Place, Suite 250 Maynard, MA 01754 Phone: (978) 461-0449, ext 11 http://www.sisoft.com-- Kevin M. Fisher Consultant Signal Integrity Software Inc. 6 Clock Tower Place, Suite 250 Maynard, MA 01754 Phone: (978) 461-0449, ext 11 http://www.sisoft.com
|------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just 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 email a written request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993
This archive was generated by hypermail 2b28 : Wed Aug 21 2002 - 07:11:10 PDT