Subject: RE: [IBIS-Users] Non_monotonous data in IBIS models
From: Ingraham, Andrew (Andrew.Ingraham@hp.com)
Date: Mon Aug 19 2002 - 07:37:26 PDT
> Thanx for the response.But just wanted to know if this non-monotonic behaviour will be the case for input only or output only buffers also ? The models that I am using are input only and output only buffers .
> I don't have any Bi-di buffer .The output buffer is 3-state output buffer .
Sorry, I really should have said tri-stateable buffers (which effectively includes bi-dir buffers too, since they are tri-stateable).
It tends to happen when you create a buffer model that has both the * Clamp tables and Pulldown, Pullup tables.
Input buffers have only the Clamp tables, so they should be OK.
Output-only buffers that don't tri-state should be OK (if the output drivers really are monotonic) because they have only the Pulldown and Pullup tables.
The monotonicity tends to happen as a result of subtracting the Clamp currents from the total currents, to get the Pulldown and Pullup tables.
If input-only buffers or output-only buffers (that don't tri-state) cause non-monotonic warnings, then they really are non-monotonic (or there's something wrong with the measurements or simulations used to create their IBIS models).
Regards,
Andy
|------------------------------------------------------------------
|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 : Mon Aug 19 2002 - 07:55:00 PDT