The problem with vendors giving you multi-GHz IBIS models is that accurate differential logic models in IBIS such as CML require someone who really understands both IBIS and SPICE to generate. Many of the IC vendors don't want to spend the time (time=money) to learn how to do it right. I have some good CML differential IBIS models from Intel that also tell you how to implement pre-emphasis and they work in Cadence Allegro PCB SI. I haven't seen anything comparable from other chip vendors. -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of sunil.mekad@xxxxxxxxx Sent: Thursday, May 26, 2005 12:06 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] SI models at MGH speeds Hi, Can anyone tell me why it is difficult to generate IBIS models for mutli-giga hz devices. Most of the vendors give us HSPICE models. Is it something to do with difficulty in accurate characterisation of V/I curve at such high frequencies (>5GHz)? In any case are HSPICE models also the correct solution? Presuming such interfaces also have pre-emphasis and de-emphasis. Cadence suggests the use of macromodels for MGH applications however, is it possible to convert HSPICE models to accurate macromodels for simulation in SPECCTRAQUEST for >5GHz application? Thanks Sunil Confidentiality Notice=0D The information contained in this electronic message and any attachments to= this message are intended for the exclusive use of the addressee(s) and may contain confidential or= privileged information. If you are not the intended recipient, please notify the sender at Wipro or= Mailadmin@xxxxxxxxx immediately and destroy all copies of this message and any attachments. ------------------------------------------------------------------ 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