Anders, I have used DDR1 in point-to-point application on several designs. The trace length is about 1.8" and the only termination I use is a series resistor on Strobe and Data lines at the DRAM end, since my ASIC drivers are weaker than the DDR drivers. Frankly I do not have card real estate to implement full DDR termination methodology. The only problem I experienced was in my very first design due to crosstalk, as I had not done crosstalk simulation under worst switching conditions. Hence it is good to simulate your topology under different conditions, and also to choose the right termination value. Regards, Ravinder Server PCB Development Hitachi Global Storage Technologies Email: Ravinder.Ajmani@xxxxxxxxxxxxxx "Anders Frederiksen" <af@xxxxxx> Sent by: si-list-bounce@xxxxxxxxxxxxx 02/03/2005 02:00 PM Please respond to af To: si-list@xxxxxxxxxxxxx cc: From: si-list-bounce@xxxxxxxxxxxxx Subject: [SI-LIST] DDR-1 termination (short point-to-point) I'm connecting a lot of DDR1 ram to a FPGA (Virtex2pro). Common schemes recommended is "embedding a DIMM design" (which would be plain stupid imho) and doing a full parallel termination in both ends (typically in 0402). The latter is naturally sensible - but it occurs to be kind of a overkill for ponit-to-point lines of "only" 5cm (~2") or less. Has anyone experience with simpler termination schemes? I mean for standard busses one would rely on slow drivers only... Cheers, Anders ------------------------------------------------------------------ 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