Subject: [IBIS-Users] Questions about Bus Hold (2nd try)
From: rob.mataheroe@philips.com
Date: Tue Nov 12 2002 - 07:24:38 PST
Hello Ibis collegues,
I want to make accurate IBIS models for input buffers and I/O buffers with bus hold.
Existing models, I have seen on the web, show the bus hold characteristic in the ground clamp curve.
When running the IBIS checker, this causes non-monotonic warnings.
Therefore I am not sure whether this way of modeling is correct.
This brings me to the following questions:
1. If the bushold characteristic is present in the ground clamp curve, how would you qualify this:
1a Wrong, since it causes non-monotonic warnings
1b. Useless
1c. Okay, since it represents the actual behavior.
1d. Other ....
2. The IBIS standard describes the Bus Hold Submodel.
I assume the Top Model describes the buffer without bus hold characteristic.
From the IBIS standard I cannot understand what part of the circuit I must simulate in order to gather the data for the Bus Hold Submodel, namely the pullup, pulldown and last but not least the ramp figures.
Of course those who have designed the IBIS standard must know the idea behind the Submodel.
Therefore I would appreciate it very much if somebody could tell me:
2.1 Which part of the circuit is described by the sub model?
2.2 How can I get more information about this subject?
Thank you in anticipation for your reactions.
Kind regards,
Rob
________________________________________________________
Rob Mataheroe Philips Semiconductors bv
P.G. Logic Product Group PD&S Building AM1.108
Senior Design Modeling Engineer Gerstweg 2
Tel. ++31 (0)24 353 2370 6534 AE Nijmegen
Fax. ++31 (0)24 353 2820 The Netherlands
Email: Rob.Mataheroe@philips.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 : Tue Nov 12 2002 - 07:37:06 PST