4 Replies Latest reply on Jul 23, 2013 11:31 AM by cbedard

    Trouble assigning net name change to a single node

    cbedard

      Hi all, before I start please know I am mostly a layout guy so my expertise in Logic is limited.

      I have a Test Point(which in Logic is jsut a 1 pin connector and in Layout is a round exposed Copper pad) that has a net name assigned to it by use of an Off Page Connector.  When I attempt to change the net name by Net Name Properties my only option is to either combine the nets or cancel the action.  I do not want to combine the nets, I just want this NODE of the net to change names.

      The only way I know to make this happen is to select the Connection, delete it and then to add a new Off Page connector and assign it to the desired net name. (not to mention how CRAZY it makes me when all kinds of vias go POOOF, GONE when I sync that change into the layout!!  Alas, that is a "kind of" layout problem so I won't hold you guys to it here.  lol)

       

      1. Is there not a facility in PADS Logic to allow changing this particular node of the net only instead of combining the nets?  If such a facility does not exist, is there some logical reason why?

       

      2. Is there some other type of entity available for use in PADS Logic that would allow for changing the net name on this one node of the net only?

       

      It seems pretty straight forward to me to only want to change one piece of a net to another net name but maybe I am missing something here.  I've attached a picture of what I am talking about. The other areas in the schematic associated with this net name are either assicated with an Off Page Connector or a Net Name Label.

       

      Thanks for any info!

       

      Chris

        • 1. Re: Trouble assigning net name change to a single node
          jduquette

          Chris, I don't understand your question, especially if your experience is in layout.  It sounds like you want to name a testpoint 'NetB' on a net named 'NetA'?  It seems like you are breaking the net into two subnets.  I think I'm still missing something...

           

          When you change a pin-pair PADS rips it out of the layout and makes you start from scratch.  I've gotten around this occasionally by making all the mods in Layout and all the mods in Logic, essentially to bypass the ECO process.  The next time I sync the designs it sees no changes and leaves everything alone.

           

          I put a label on all of my test points, so then I can name it whatever I want.  Is that what you are looking for?

          • 2. Re: Trouble assigning net name change to a single node
            cbedard

            I just meant that my experience is mainly in Layout so I won't be surprised to hear that I might be "mis-using" Logic if that is the case.

             

            So to clarify the situation.(hopefully)

             

            I've got an existing design in both Logic and Layout...

            There is an existing net T1_C that the test point TP10 is assigned to.  There are other items on the T1_C net as well.

            There is also another existing net called T1_A with many items as well.

             

            My problem is that in Logic if I select the text "T1_C" on the Off Page Connector that is connected to TP10 and change it to "T1_A" I then get a pop up asking me if I want to combine the nets.  My only choices are to combine the nets or cancel the action.  I don't want to combine the nets so I can't change TP10's net this way.  I can't choose the Combine Nets option because there are other items that I want to remain on the T1_A net as well as on the T1_C net.  I just want to move TP10 logically from the T1_C net to the T1_A net.

             

            Still in Logic here... It seems like I have to completely delete the Off Page Connector from TP10.  This removes any & all nets from TP10.  If I then Sync it does blow away TP10's connection to the T1_C net.(logically & physically)  Then if in Logic I add a new Off Page Connector with the Net Name T1_A and Sync, as expected TP10 will now be on the T1_A net.  This is what I want, but is all of that necessary?

             

            Does all of that really need to happen just to move TP10 from the T1_C net to the T1_A net without affecting the rest of both of those nets?

            • 3. Re: Trouble assigning net name change to a single node
              jduquette

              Okay, I think I understand.  The trick is you need to select a Connection and not a Net when you rename part of a net.  You can then pull up the properties on the connection and rename it; just make sure you have 'This instance' checked (i,.e. subnet) and not 'All instances'  (i.e. entire net) before you hit <Okay>.  That only renames the subnet instead of the entire net  Note that you'll need to rename the subnet with T1_C to another name (DummyNet for example).  You now have three nets instead of two.  Now repeat the process and change DummyNet to T1_A and say yes when you want to merge the two nets.  Now TP10 is on T1_A and not on T1_C.

               

              How's that for Logic?!?

              • 4. Re: Trouble assigning net name change to a single node
                cbedard

                Ahhhh, OK.  I'll buy that.  Just select the Connection and initially give it some crazy net name.  Then do it again and assign it to the net you want and this time it's OK to combine the nets because you are only moving the one item you want to onto the existing net.

                 

                OK that works.  It didn't occur to me to use an interim net name.

                 

                Thanks!

                 

                Chris