Nikhil, The length of the PRBS used depends on what you're trying to do. If you're simulating a serial channel, you would use a PRBS that has a maximum run length that is as large or 1 bit larger than the worst case pattern run length in the channel. For 8B10B encoding, the maximum run length is 5 bits, so a PRBS7 would be adequate for simulation purposes. If you are concerned with pattern dependent ISI, then you'll need a pattern that is long enough to just encompass the channel memory time. Channel memory time is the time that it takes for a channel to return to it's quiescent state after a unit impulse excitation, or a unit step excitation. It is the amount of time in bits, that it takes for all ringing to dampen and die off. I would usually use a PRBS pattern that is 1 bit longer than the expected channel memory time, just to be sure. regards, Scott Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com Teraspeed® is the registered service mark of Teraspeed Consulting Group LLC npatel@xxxxxxxxxx wrote: > Hello all, > > I wanted to know if there is a way to determine what stimulus pattern > and length would be adequate to use in SI simulations. For example 32 > bit PRBS, 24 bit PRBS etc. > > How does one find out which stimulus will cover all scenarios. > > Thanks, > Nikhil =20 > ------------------------------------------------------------------ > 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