2 Replies Latest reply on May 11, 2018 3:26 PM by David Ricketts

    Differential Pair editing

    ritu
    ritu May 10, 2018 12:00 AM

      PADS VX 2.1

      The Differential pair editing(adding serpentines) required to do length matching with other differential nets is so time consuming and error prone.

      The gap is not maintained normally at the turns.

      When the latium check is run in layout, it results in so many errors related to gap in differential pairs. Correction of these in Router is another problem as it is very tedious and

      you can't be sure that the error has been removed. there is no provision of latium error checks in Router.

      Again you need to come to Layout and run the check.

      Any solution to this?

       

      Moreover Clearance option is not available in Router for "Item to item" clearance.

       

      Regards,

      Ritu

        • 1. Re: Differential Pair editing
          vinayarora
          vinayarora May 10, 2018 10:23 AM (in response to ritu)

          We never use Latium rule checking.

           

          Are you routing with DRC in prevent mode or not?

          • 2. Re: Differential Pair editing
            David Ricketts
            David Ricketts May 11, 2018 3:26 PM (in response to ritu)

            Layout is using code from the Router for Latium error checks. Latium is the technology Router is based on. So Router DRC IS Latium DRC.

             

            Enable "Show guard bands on object" to see the spacing when routing and editing.

             

            Use the Stretch command to edit and move diff pairs around. Using a smaller grid when you do this is usually helpful. You can visibly see any spacing error when selecting any trace with guard bands on. Always keep DRC on when doing this.

             

            Design Verification has a specific setting for Diff Pair spacing with adjustable error conditions.