Hi Girish-- There really aren't routing guidelines for carrier cards for PCI-X since topologies for the bus can vary so widely, since it is typically a multi-drop bus. The add-on cards have specs so that they are a fixed entity around which you can design your carrier card. This also brings up an important issue about looking at "delay" versus length. Especially for a bus like PCI-X which employs common-clock timing, calculating accurate "flight times" for your signals is especially important. Flight times include the effects of loading of the receiver and effects of reflections from connectors, vias, etc. in addition to the interconnect delay. Flight times are also correlated to the internal chip timing (in this case Tco) so you can make sure you are meeting your complete system timing. Once you have calculated the min and max flight times for your signals to meet your setup and hold requirements, you can test different routing lengths in simulation to see what length range meets your flight time requirements. It will be a little easier for you if you are just doing a point-to-point PCI-X 133 interface, which is the most common. (Although if I remember correctly, you can make a multi-drop PCI-X 133 interface work with careful planning). When calculating timing, you can also add in some extra margin for things like crosstalk and jitter. Although the more effects you actually include in your simulation, the less you have to guess at how much margin to add. There is a recorded webinar on PCI-X design avilable at www.mentor.com/hyperlynx if you click on Multimedia and go to the last page. Or the direct link, which is kind of long, is: http://www.mentor.com/products/pcb-system-design/multimedia/overview/tra de-offs-in-pci-x-interconnect-design-912ee4dd-6beb-4e84-8479-a7a7143b7d8 8 The presentation is based on our PCI-X Design Kit. --Pat Patrick Carrier Technical Marketing Engineer High Speed Design Mentor Graphics Corporation Patrick_Carrier@xxxxxxxxxx ph. (512) 425-3015 -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Girish Gopi Sent: Thursday, July 02, 2009 5:22 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] max. & min. routing lengh of PCI X133Mhz Hi there, I am using the PCIe to PCI-X bridge (P17C9X130DNDE from pericom). http://www.pericom.com/pdf/databriefs/PI7C9X130_db.pdf I am unable to findout the routing guidelines for the PCI-X 133MHz signal in the carrier card. PCI-X spec and other documents what ever i refered has only routing guidelines for the add on cards. Is there any recommendation for the min and max trace length for the carrier card PCI-X 133MHz? How to calculate the min and max trace length? Thanks in advance Girish Gopi **************** CAUTION - Disclaimer *****************This email may contain confidential and privileged material for the sole use of the intended recipient(s). Any review, use, retention, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender by reply email and delete all copies of this message. Also, email is susceptible to data corruption, interception, tampering, unauthorized amendment and viruses. We only send and receive emails on the basis that we are not liable for any such corruption, interception, tampering, amendment or viruses or any consequence thereof. *********** End of Disclaimer ***********DataPatterns ITS Group********** ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net 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 technical documents are available at: http://www.si-list.net 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