5 Replies Latest reply on Apr 26, 2016 2:27 PM by marksb

    Trace length matching on the MGTs and routing lengths of other signals

    marksb

      Are the trace lengths matched on all the MGTs and between the MGTs?  Ie. The diff pairs are matched length but are the channel to channel lengths also length matched?

      Is there a table of routing lengths for the FPGA signals connected to the JX1 and JX2 connectors?

        • Hi there,
          drozwood90

          Hi there,

          The JX1 MGT data pairs are length matched within the pairs and routed to <100 mils pair to pair.

          --Dan

          • How about JX2
            marksb

            Thanks for the info.  I still have a couple questions.

            Is the matching the same on JX2?
            Are the pairs on JX1 routed to the same length as the pairs on JX2 to <100 mills?

            • How about JX2
              marksb

              Thanks for the info.  I still have a couple questions.

              Is the matching the same on JX2?
              Are the pairs on JX1 routed to the same length as the pairs on JX2 to <100 mills?

              • Hi there,
                drozwood90

                Hi there,

                I did a little more looking and discovered that when the board was in layout, they used the guidance of:
                JX1 MGT data pairs are length matched within pairs and routed to < 100mils pair to pair.
                JX2 MGT data pairs are length matched within pairs and routed to < 25mils pair to pair.
                All JX1 and JX2 MGT data pairs are length matched within pairs and routed to < 100 mils pair to pair.

                I do not see any specification of matching JX1 to JX2, only the MGT pairs and pair to pair listed above.  As I read this, if there is a MGT data pair that is on JX1 and a second MGT data pair on JX2 they would be <100 mils to each other, however as I read this it would ONLY be those pairs across the connectors.  There is no specification that I was able to locate that states JX1 has any relationship to JX2 - except those listed above.

                --Dan

                • Thanks for checking
                  marksb

                  Thank you for checking into this.