Hi, I am also looking for the same informations. where can i get the standard guidelines for DDR-SDRAM layout. I am using multiple DDR-SDRAM chips to form a DDR-bank on board. Thanks, Sanjay -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of zheng qi Sent: Wednesday, September 27, 2006 8:09 AM To: AlexLi@xxxxxxxxxxxx Cc: Edi.Fraiman@xxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: DDR interface hi I think ck and dqs belong to different clock domin .so match them does really meaningful ??? 2006/9/27, Alex Li <AlexLi@xxxxxxxxxxxx>: > Hi, Edi: > On DDR layout, you can routing DQS/DQ(DM)/Clock with same lengrh. > =20 > On DDR2 layout, you can routing DQS and Clock with same length. > But data and data mask must be shorter than DQS > =20 > B.R. > Alex Li > > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] > On Behalf Of Fraiman, Edi > Sent: Tuesday, September 26, 2006 9:50 PM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] DDR interface > > Hi all, > > I have question about DDR interface layout. > I understand that during PCB layout the DQS (data strobe) should be > routed with same length as DQ (data), DQM signals and > Address bus and control signals (RAS,CAS, CKE,WE,CS) should be aligned > to clock. > But I do not understand what relationship (what the maximum difference > in length) between DQS and CLOCK. > Could you please advise? ------------------------------------------------------------------ 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 http://www.patni.com World-Wide Partnerships. World-Class Solutions. _____________________________________________________________________ This e-mail message may contain proprietary, confidential or legally privileged information for the sole use of the person or entity to whom this message was originally addressed. Any review, e-transmission dissemination or other use of or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you have received this e-mail in error kindly delete this e-mail from your records. If it appears that this mail has been forwarded to you without proper authority, please notify us immediately at netadmin@xxxxxxxxx and delete this mail. _____________________________________________________________________ ------------------------------------------------------------------ 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