4 Replies Latest reply on Nov 26, 2014 2:34 AM by robert_davies

    DRC in DXDesigner for ripped net not contained in bus

    tom.brady

      Hello,

       

      I have looked through all of the DRC rules in DXDesigner for incorrectly ripped net but I couldn't find anything. Here is an example:

       

      A bus called RGB contains bits RGB(0:23). A net is incorrectly ripped called "xabc". When I compile the design, it does not report an error and the DRC rules do not report an issues. The packager runs fine and compiles.

       

      Is there a way to check for the issue?

       

      Thank you.

        • 1. Re: DRC in DXDesigner for ripped net not contained in bus
          agxinmj

          Hai,

                 when buses are created with net names RGB[0:23] rip nets will not create nets with net names "xabc "

          can you please provide the snap short of the ripped one

          regards

          AGXIN.J

          • 2. Re: DRC in DXDesigner for ripped net not contained in bus
            robert_davies

            Currently there is no DRC check for this, creating such a connection will have created an alias as you cannot connect such a connection using the 'rip nets' functionality as Agxinj indicated in his reply. In the forthcoming VX.1 release there is a new check for unused bus members and one for aliased nets, this second check will most likely pick up the type of connection you describe.

            1 of 1 people found this helpful
            • 3. Re: DRC in DXDesigner for ripped net not contained in bus
              aclark

              I have seen something similar happen in EE7.9.4u6

               

              It seems that what happens is that the connection to the bus is controlled by the net ripper - and it isn't even a "property" of the ripper (if you select the ripper and open the properties dialogue, it doesn't tell you which connection it is).  If you select the ripper and hover over it, it will tell you the actual connection.

               

              We've seen a few cases of nets ripped e.g. bit "10", but the actual net has a netname of DATA[3] - in this case, you assume that it is bit 3, but it is actually bit 10!

               

              I would suggest that you select the option in Setup --> settings --> Advanced --> "Show Ripper Indexes"

               

              This will show the bit number in simple busses (e.g. "10" in the above case"), but in more complex busses the whole name (e.g. "write_strobe").  You will probably find that your ripped net is succesfully ripped from the bus, but it's not obvious which net it is.  In the clip below, you can see the netname, the ripper index "0" which matches, and the pop-up box:

               

              Net_ripper.png

              • 4. Re: DRC in DXDesigner for ripped net not contained in bus
                robert_davies

                As DxDesigner connects by net name it is not good practice to systematically alias nets throughout a design, use the net names as defined in the bus or bus content and if you need to alias nets do so sparingly.