You can also do a detailed static timing analysis with simulations from a simulator that uses IBIS models to provide the delay times to see what your timing margins are. Run a cross-talk analysis with the same tool. Having someone do this in parallel with your lab work could find the problem quicker if it is related to timing or cross-talk. SSN is harder to simulate with just ibis models and data sheet info for a part but there are some tools that help. -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Fraiman, Edi Sent: Wednesday, August 02, 2006 3:30 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] DDRAM BUS Testing Hi, I'm working on a design that includes FPGA with DDRAM controller and several DDRAM chips. The traces goings direct from FPGA to DDRAM with necessary pulll up resistor to Vref. (SSTL interface) without any debug connector. Sometimes we have productions problems. It is very difficult to find what bit in bus between FPGA and DDRAM is shorted or disconnected. Could somebody give any tips how it's possible debug DDRAM busses in terms of production issues. Best regards, Edi Fraiman - - - - - Appended by Scientific Atlanta, a Cisco company - - - - - This e-mail and any attachments may contain information which is confidential, proprietary, privileged or otherwise protected by law. The information is solely intended for the named addressee (or a person responsible for delivering it to the addressee). If you are not the intended recipient of this message, you are not authorized to read, print, retain, copy or disseminate this message or any part of it. If you have received this e-mail in error, please notify the sender immediately by return e-mail and delete it from your computer. ------------------------------------------------------------------ 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