Radovan, This could be also a problem with s2ibis. If you are careful with time correlating the Vt data you generate with the stimulus that triggered it, then you should be able to get correct waveform overlays between your SPICE and IBIS models. Watch out for the threshold levels on the SPICE model's input, and the slope of the stimulus on it also... Arpad ================================================================== ________________________________ From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf Of Radovan.Vuletic@infineon.com Sent: Monday, July 11, 2005 5:52 AM To: ibis-users@eda.org Subject: [IBIS-Users] Differences between Hspice netlist simulation and Hspice B-element simulation - bug or feature? Hi IBIS Experts, I have extracted IBIS model. To check the quality of this model I have compared the results of simulation on Hspice B-element with simulation on netlist - that means, I have used exactly the same stimuli applied on B-element and on netlist (IBIS is extracted out of this netlist). What is disturbing me is that I see a difference between B-element and netlist waveforms, i.e. B-element is always delayed in comparison to netlist result. What is even more disturbing is that this delay is not the same for rising and falling edge. Rising edge of B-element is delayed for around 20ps and falling edge of B-element is delayed for around 40ps. I have a feeling that this delay is somehow connected with transient analysis step (.TRAN 1.96e-11 1.96e-09) but I am not sure. Once again, I apply exactly the same stimuli on B-element and on netlist (and of course the same termination - load). Has that to do something with some version of Hspice or it is a problem of IBIS extraction tool (s2ibis2)? So the question is: Is this difference between B-element and Hspice bug or feature? If it is bug is it a problem of s2ibis2 or I perhaps the question what is Hspice doing with B-element? And finally - what should I do to repair the problem? Many thanks for any advice! Radovan Best regards / Mit freundlichen Grüßen / S po¹tovanjem Radovan Vuletiæ Infineon Technologies AG MP PD PDE Room 03.911 Balanstraße 73 D-81541 München Phone: +49 (0)89 234 20108 Fax: +49 (0)89 234 27705 Fax (PC): +49 (0)89 234 955 5305 E-mail: radovan.vuletic@infineon.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 1993Received on Mon Jul 11 08:58:44 2005
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