Hello, Heinrich, Normally, a model has two rising and two falling waveforms. These have the same R load, with different voltages (typically the signal's Vhi and Vlo). This tells the simulator how the driver pullup and pulldown devices turn on and off. Simulation tools then use these to predict V(t) and I(t) for a load. The algorithms are presented in the following publications: http://www.ntu.edu.sg/home/ehntan/glsvlsi.zip http://www.sigrity.com/papers/ectc96/DOectc96ibis.htm Best regards, Lynne "IBIS training when you need it, where you need it." Dr. Lynne Green Green Streak Programs http://www.greenstreakprograms.com 425-788-0412 lgreen22@xxxxxxxxxxxxxx -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Heinrich.Smith Sent: Thursday, March 03, 2005 1:07 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Double Rising Waveform and Falling Waveform in one IBIS model Hi, all In some IBIS model, you may notice that some have two rising waveform sections and two falling waveform sections with different test fixtures in one model. And I wonder how the model works with these double rising waveforms and double waveforms at the same time while the simulation goes on. If anybody get ideas about this, please tell me the story. I'll be really very appreciated!! Thx ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu