Ramiro, Another approach to use for ODT is the submodel in the form of [Add Submodel]. Since you're indicating you want to use this for an input structure you should use the Non-Driving mode. You would then use the Dynamic_clamp form of Submodel_type. This approach is more complex and, therefore, probably only worthwhile when the termination scheme warrants it. For example, an active form of termination with a non-linear V/I characteristic. A simple, linear form is easiest to handle in the clamp tables. The submodel form makes it very clear to the user (who reads the .ibs file - poor, sad soul) that it's there, whereas 'hiding' it in the clamps will make it less evident. That said, I certainly wouldn't use the submodel for this reason; something in the Notes section of the .ibs file can readily let users know it's there in the clamps. The IBIS spec. provides the answer to your question about when you can (in fact, must) use Model_type Terminator. It also has a bearing on your question about you having to use the [Rgnd] and [Rpower] keywords:- "If one or more of [Rgnd], [Rpower], [Rac], and [Cac] keywords are used, then the Model_type must be Terminator." Be aware that your IBIS simulator tool will probably treat this type of pin completely different than it treats an Input type. For example, this type of pin may well be disregarded for timing measurements, understandably, and it may be disregarded for signal integrity measurements. Note that these are not the only keywords that can be used in a Terminator Model_type. A resistor model that uses [Series Pin Mapping] and [R Series] could be of type Terminator. Regards, Tony -----Original Message----- From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf Of RODRIGUEZ_LECONA_RAMIRO Sent: Monday, February 14, 2005 4:12 PM To: ibis-users@eda.org; ibis-info@eda.org Subject: [IBIS-Users] on-die termination Hi all, How can I include on-die termination for an input structure in an IBIS model? Some people say that one way to include on-die termination is to use superposition and add the termination currents to the diode currents in the clamp sections. However this action is going to avoid that the clamp curves reach the zero value so the IBIS parser will report a error message. Do I have to use the keywords Rgnd and/or Rpower? When can I use "terminator" as my [model type]? Thanks. Ramiro |------------------------------------------------------------------ |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 |------------------------------------------------------------------ |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 1993Received on Mon Feb 14 20:55:03 2005
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