Hectic? ...simpler?? Wow, a while back I was matching the DDR interface manually using a calculator (without Xnets!). I guess these days people just want a magic wand effect!! Once you figure it out and set it up in one design, you import it into all that follow. Good luck, not sure how it works with Studio Performance though. Gary Gary E. MacIndoe PCB Design Engineer Fort Collins, Colorado amd.com gary.macindoe@xxxxxxx ________________________________ From: icu-pcb-forum-bounce@xxxxxxxxxxxxx [mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Chew Wang Sent: Wednesday, May 23, 2007 6:20 AM To: icu-pcb-forum@xxxxxxxxxxxxx Subject: [PCB_FORUM] Constraint Manager Hi all, I have DDR connections coming to DDR DIMM (J3) from processor (U1) thru the series termination. It also has the VTT end termination. I have defined the net as Xnet, as it makes my length matching simpler. Now the problem is: While using Constraint manager, I need to define pin pair for the match group. Because I am not bothered regarding the length from DIMM to end (VTT) terminations. So I create pin pairs from U1 to J3.But I need to repeat it for all 64 bit databus,13bit address,3 clk's etc... which is very hectic work. Is there any process to make my work simpler.. Regards Chew.Wang