Doug, Thanks for the simple and easy to understand reply. Have you seen any articles etc. on the subject to dig deeper. Regards Ibrahim -----Original Message----- From: Douglas Burns [mailto:dburns@xxxxxxxxxx]=20 Sent: Sunday, August 11, 2002 12:52 PM To: Ibrahim Khan Cc: si-list@xxxxxxxxxxxxx Subject: Re: [SI-LIST] ISI Ibrahim, If you think of each bit of data as a "Symbol",then inter-Symbol Interference (ISI) is the effect preceeding symbols have on the current symbol. ISI is caused when a symbol is driven before the network has settled from a previous symbol. This means that the new symbol is being driven from a different operating point than other symbols. ISI can be predicted by deteriming the settling time of the network in question. A simple simulation of a single edge driving your network will give you the network settling time (or you could estimate just by looking at the total network length. To avoid ISI,You must operate your network such that you never drive faster than the network settling time. In general,this is impractical and you need to setup your simulation environment to identify the affects ISI will have on your circuit. Doug Douglas Burns Signal Integrity Software, Inc. 6 Clock Tower Place Maynard,MA 01752 www.sisoft.com > SI Gurus, > > Can you please explain in simple term what is: > > 1. Inter-Symbol-Interference > 2. How to predict (based on the data sheet etc) that we will encounter > ISI 3. How to avoid it > > Any literature out there that will explain it. > > regards > Ibrahim Khan > > ------------------------------------------------------------------ To=20 > unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with=20 > 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to:=20 > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > 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 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