Dear IBIS experts I am currently looking at the Rref_diff subparameters under the [model] keyword and the usage of this subparameters. This subparameters is only available in IBIS specification of v4.1 but not in older version. May I know how this subparameters keyword is being used? the detail of the question is as below. IBIS Spec: Rref_diff is used for true differential buffer timing test loads. where the buffer hv to be specified only when the [Diff Pin] keyword connects two models, and each buffer references the same model. The Rref_diff and Cref_diff subparameters can be used with the Rref, Cref, and Vref subparameters for a combined differential and signal-ended timing test load. 1. My questions will be, can this Rref_diff sub-parameters be used ONLY when we engaged using the true differential [External Model] with either spice or vhdl-ams? As shown in the IBIS spec. 2. Can this Rref_diff keyword be used in the context of a normal true differential buffer under the [Model] keyword, and at the same time the model is define under [Diff Pin] section to describe the timing test loads just like how the rest of the Cref, Vref keyword are used to facilitate for board-level timing simulation, with the setup as attached. Can the Rref_diff keyword used under the example below? [Model] 25_lvds Model_type Output Polarity Non-Inverting Enable Active-Low Rref_diff = 100 Vmeas = 1.163 C_comp 1.8pF 1..8pF 1.8pF Please kindly comment. Thanks. Regards Cynthia -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org |with 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 e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993
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