I believe you can do this by defeating the phase tolerance (make it big) then applying a relative prop delay. -Bill ? wrote: > I don't think you can setup an exact difference for a diff pair. > We use the uncoupled length, Gather control = ignore and then setup max mm > and phase tolerance. > On our chips the the general rule is that the trace should be equal lenght > from the BGA edge. > Another ways is to include the first peace of trace in the connector/chip > symbol. > Finally you can make a clength report including delay and import it into > excel to check the lengths > > Hi > Peter Sørensen > MTS Engineer > Ethernet Product Group > Vitesse Semiconductor Corporation > Location: Hørkær 16, 2730 Denmark > Tlf +45 4485-5996 > Cell +45 4050-7098 > Fax. +45 4485-5939 > > > > > > > -----Original Message----- > From: Musetti, Carl [mailto:cmusetti@xxxxxxxxxxxxxxxx] > Sent: 8. december 2004 15:48 > To: icu-pcb-forum@xxxxxxxxxxxxx > Subject: [BULK] - [PCB_FORUM] Differential Pairs on 15.2 > > > Hi All, > > Has anyone had to deal with differential pairs in 15.2 that are not > balanced out of the IC. The Mellanox > InfiniHost_III_MT25208 spec that the PCIX bus diff pairs are not balanced out > the chip and give the skews and states that the skew must be accounted for on > the PC layout to balance the pair completely end to end. How would I > configure this rule in allegro? For instance is there a way to tell the tool > to route the + end 50 mils longer than - end? > > Thanks for all replies in advance > > Carl > > ************************************************************ > * Carl T. Musetti Infinicon Systems * > * Tel: 610-233-4828 680 American Ave, Suite 100 * > * Fax: 610-233-4777 King of Prussia, PA 19406 * > * cmusetti@xxxxxxxxxxxxx * > ************************************************************ > > ----------------------------------------------------------- > To subscribe/unsubscribe: > Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx > with a subject of subscribe or unsubscribe > > To view the archives of this list please login at > //www.freelists.org. Our list name is icu-pcb-forum > or go to //www.freelists.org/archives/icu-pcb-forum/ > > Problems or Questions: > Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx > > Want to post a job listing ? DON'T DO IT HERE! > Better yet, join our jobs listing forum. > > SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx > POST: icu-jobs-forum@xxxxxxxxxx > ----------------------------------------------------------- > ----------------------------------------------------------- > To subscribe/unsubscribe: > Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx > with a subject of subscribe or unsubscribe > > To view the archives of this list please login at > //www.freelists.org. Our list name is icu-pcb-forum > or go to //www.freelists.org/archives/icu-pcb-forum/ > > Problems or Questions: > Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx > > Want to post a job listing ? DON'T DO IT HERE! > Better yet, join our jobs listing forum. > > SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx > POST: icu-jobs-forum@xxxxxxxxxx > ----------------------------------------------------------- -- Bill Gerner Voice: (781) 442-2649 x22649 Fax: (781) 442-1651 x21651 Email: william.gerner@xxxxxxx Sun Microsystems 1 Network Drive Burlington, MA 01803;MS UBUR02-205 ----------------------------------------------------------- To subscribe/unsubscribe: Send a message to icu-pcb-forum-request@xxxxxxxxxxxxx with a subject of subscribe or unsubscribe To view the archives of this list please login at //www.freelists.org. Our list name is icu-pcb-forum or go to //www.freelists.org/archives/icu-pcb-forum/ Problems or Questions: Send an email to icu-pcb-forum-admins@xxxxxxxxxxxxx Want to post a job listing ? DON'T DO IT HERE! Better yet, join our jobs listing forum. SUBSCRIBE: icu-jobs-forum-subscribe@xxxxxxxxxx POST: icu-jobs-forum@xxxxxxxxxx -----------------------------------------------------------