Hi Terence, Internal delay of IBIS buffer delay is involved in the V/T data, when using spice2ibis utility to generate IBIS buffer model, you may find this situation. As I know, IBIS buffer in HSPICE contains the internal delay, about the cause of 100~300ps difference, I think it is yielded by input stimulus rise time Trise. The buffer delay in HSPICE will be a constant which is showed in V/T data, and not change according to Trise, however, the actual responding including the buffer delay is a function of Trise ( may have other factors ). I guess that buffer delay in spectraquest is cut off from V/T data. Hope this can help you. best regards slwu TerenceHsieh@xxxxxxxxxxxx wrote: > Dear all > Is any one know that if the V/T waveform in ibis include > buffer delay? I have compared the output waveforms of (1)spice > file, (2)ibis in spice and (3)ibis in borad simulation tool(specctraquest). > There are some difference in delay (between (1)(2) about 100~300ps; > between (1)(3) the delay difference will > 1ns ). Is this condition normal? > How could I generate more accurate waveform? > Terence > > ------------------------------------------------------------------ > 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