Hi Eckhard. That seems like a reasonable practical approach I can agree with, if I have both values and I make the model. But from an IBIS perspective it is not clear from the spec how to interpret this info in a model. When I get a model from a manufacturer with this data already there, how do I know which it is? The IBIS standard does not seem to be specific here. So if the manufacturer did put in the destructive undershoot like -1.0V and we simulate the design and fulfill this figure, we are not sure it will function correctly? By the way in your example I think you turned the values around. destruction below -0.3V and malfunction below -0.4V I suppose you meant: destruction below -0.4V and malfunction below -0.3V Best /Anders ________________________________ From: Lenski, Eckhard (NSN - DE/Muenich) [mailto:eckhard.lenski@nsn.com] Sent: den 4 mars 2008 12:44 To: Anders Ekholm; ibis@eda.org Subject: AW: [IBIS] Overshoot/Undershoot specs. Hello Anders, 1) General if I interpret your question correct, you are looking for another overshoot parameter e.g.. classic: s-overshoot-low : -0.3V d-overshoot-low : -1.0V d-time: 2ns new : s-overshoot-low-destroy : -0.3V s-overshoot-low-funtion : -0.2V d-overshoot-low (-destroy) : -1.0V d-time: 2ns it might be even possible, that this could be applied to the dynamic values as well. 2) Treatment at NSN: I assume, that at the moment, we are taking the warnings/errors from overshoot in this way both cases will be bad for the design, either the device will be destroyed, or it will malfunction. So we are using the worst case for the overshoot parameter, ( if both of these informations exist ) e.g. destruction below -0.3V and malfunction below -0.4V we are using the more restrictive for s-overshoot-low so s-overshoot-low would be -0.3V 3) What to do : so either the spec should describe this more exactly, or if the community finds it necessary, we should write a bird and ask for additional overshoot parameters Mit freundlichen Grüßen / Best regards / Cordiali saluti / ystävällisin terveisin Eckhard Lenski Nokia Siemens Networks GmbH & Co. KG COO RA RD BTS HW GERAN BTS&NB&CP Dev SDE CAE libraries and models Balanstr. 59 81541 München Germany phone : +49 89 636 79002 fax : +49 89 636 78895 email: eckhard.lenski@nsn.com Nokia Siemens Networks GmbH & Co. KG Sitz der Gesellschaft: München / Registered office: Munich Registergericht: München / Commercial registry: Munich, HRA 88537 WEEE-Reg.-Nr.: DE 52984304 Persönlich haftende Gesellschafterin / General Partner: Nokia Siemens Networks Management GmbH Geschäftsleitung / Board of Directors: Lydia Sommer, Olaf Horsthemke Vorsitzender des Aufsichtsrats / Chairman of supervisory board: Lauri Kivinen Sitz der Gesellschaft: München / Registered office: Munich Registergericht: München / Commercial registry: Munich, HRB 163416 ________________________________ Von: owner-ibis@eda.org [mailto:owner-ibis@eda.org] Im Auftrag von ext Anders Ekholm Gesendet: Dienstag, 4. März 2008 10:53 An: ibis@eda.org Betreff: [IBIS] Overshoot/Undershoot specs. This text is taken from the 4.2 IBIS spec. --------------------------- The static overshoot subparameters provide the DC voltage values for which the model is no longer guaranteed to function correctly. Typically these are voltages that would cause the physical component to be destroyed. -------------------------- This is a bit confusing, since what we get from our component vendors are two diffrent levels, one that will garantuee function and one that will garantuee that the component is not destroyed. And sometimes we get similar data for dynamic overshoot/undershoot parameters. The question is how to interpret the spec. are the spec talking about function or are the spec disussing destruction? As a user my design will have to fulfill my function so to me it would make sense it it did specify function requirements, but as the spec is not clear here I do not know what component vendors put in their models. Is there a need to separate this two diffrent parameters in the IBIS spec? Best /Anders --------------------------------------------------------------- Anders Ekholm Senior Specialist Signal Integrity CDU and DXU HW design Ericsson Product Development Unit BTS SE-164 80 Stockholm, Sweden Tel: +46 8 404 27 58 Fax: +46 8 757 23 40 email: anders.ekholm@ericsson.com --------------------------------------------------------------- -- This message has been scanned for viruses and dangerous content by MailScanner <http://www.mailscanner.info/> , and is believed to be clean. -- 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 1993Received on Tue Mar 4 04:03:25 2008
This archive was generated by hypermail 2.1.8 : Tue Mar 04 2008 - 04:03:47 PST