0 Replies Latest reply on Apr 13, 2015 9:48 PM by agxinmj

    DDR3-PRELAYOUT SIMULATION

    agxinmj

      Hellow every one

      I simulated a P1010 Processor interfaced  to 5 ddr3 chips single rank memory

      case 1: I kept all the length TL111=TL113=TL119=TL121=TL123=TL125=0.5inch

       

      ddr3-sch-ok.PNG

      now my eye digram is good at U61.K3

      Capture-DDR-BETTER.PNG

      But in the same schematic I reduced the length of the segments to 0.2 inch

      dpt.PNG

      now my eye wave form is ever worse i canged the drive strength to full and half but still my eye wave form is worse

      what should i adjust at this length to get a better wave form

      Capture-dpt.PNG

      since my stub lengths are reduced my eye should be better but it is gettig worse

      please help to identify the problem.thanks for helping in advance

      thanks and regards

      AGXIN.J