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About Matched Lengths Between Pairs

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  • #16
    robertferanecSo you mean InNet(Track_N) OR InNet(Track_P) OR ... ?


    • #17
      basically yes, just to make it easier, put them all into a group


      • #18
        robertferanecFor group do you mean class ?
        With AD21 I noticed that when you import the schematic again you loose the classes !
        With a project as complex as this one I permanently reimport the schematic.


        • #19
          specify the net class in schematic


          • #20
            It is possible to create a netclass in the schematic.


            • #21
              Perhaps this video is interesting for you too:


              • #22
                Hi everyone,

                I found the issue and solved it.
                The issue was on my side, not Altium.

                I am happy to share the solution, it can save a lot of time for people who meet the same issue.

                To remember a little bit, I defined among others Differential Pair Routing rules at the beginning of the design.
                I also defined Matched Lengths rules, InPairs and BetweenPairs.

                As I share on 07-15-2022 (9:43 AM), I faced a problem with differential pairs length as I drag on them to tune.
                The target length was something like 900 mm !
                I found the problem while hitting the Tab key.
                This allows a you to enter the configuration for differential pair tuning.
                I noticed that AD was struggling to identify which rule to apply: there were 2 rules instead one !
                I got the rule dedicated to the differential pair selected and another one named "HDMI0_OUT" and this is this one that triggered the issue.

                While entering the different rules for Length Matching Between Pairs, I started entering this BetweenPairs rule "HDMI0_OUT" pointing to all differential pairs.
                This rule applied to all pairs and AD set the targeted length to 900 mm.
                Removing this rule solved the issue for all pairs except for a group including DP0_OUT_D0 ... D3 and CLK.

                As I shared on the same day (1:29AM), it was impossible to get the tuning box as I dragged on each differential pair of this group.
                After a long time of investigation, I finally noticed that I forgot to specify the Differential Pair Routing rule for this group.

                As soon as I fixed the issue, I was finally able to tune between pairs for this group.

                Today everything is running smoothly and I am able to tune all pairs with both InPairs and BetweenPairs rules.

                For a project inducing at the beginning about 7000 errors, I am having about 250 errors and am really enjoying to reach the goal very soon.

                That's all Folks !


                • #23
                  One thing I was wondering if the correct rule was being applied. With right-click the board and selecting Applicable unary rules.
                  I do not know if this would come up.
                  Anyhow, problem solved.