1 2 First Previous 29 Replies Latest reply on Mar 19, 2014 7:49 PM by dale.rebgetz

    Star Points - Do you need them?


      How many people out in the world of Mentor users wish to use Star points?


      That’s a via or point on the board that connect more that one net together eg GND_ANALOG1, GND, DIGRTN.


      I have been asking for this for at least 15 years. Mentor last week said to me no one else requires such a thing.

      With weight of demand we can get this developed. Leave a reply here maybe Mentor will take note.


      Other tool suppliers can do it.

        • 1. Re: Star Points - Do you need them?

          Most of us use a two pin tie point component. (Or more pins)  I use star topologies on boards and in systems.  Have for years.


          There certainly has been many requests for this over the years but we have always settled for the tie point component.



          • 2. Re: Star Points - Do you need them?

            I have also used this method in the past along with many others all are bodges and fudges. This method will generate DRC errors both within Expedition, and on the manufactures frontend tool after generating Gerber of ODB++. (We currently have a PCB that has over 2000 DRC errors using this method). Mentor suggestion is to either ignore the error or switch the error check off. Both of these suggestions are totally unacceptable. The system should be right by design. Not bodge and legit.

            • 3. Re: Star Points - Do you need them?

              In Allegro, User can assign a net_short atribute to a via or a pin where you can connect differet nets together, so user can short gndd and gnda on the one point.

              In Expedition, User also can implement shorting the shorting but using  different methods such as conductive shape or a pseudo shorting componet.


              User prefer to draw gndd and gnda seperatly and hope to both can be connect on one point in the layout. To address this issue, a special attribute needed to add in the front-ent tool and get understanded by back-end tool.

              • 4. Re: Star Points - Do you need them?

                Yes, we need Star points.


                In Boardstation we have a component with two overlapping pins, and a symbol on the schematic. Thus allowing us control how a components connect to a net in a certain fashion - We have multiple version of this geometry to cater for each layer.


                In Expedition things get slightly more complex, you can force it through netline manipulation but to be honest its not very intuative, and of course, there is no indication on the schematic. I think it is important to have this, as it then means that someone with no prior knowledge of the circuit can pick up the circuit/layout and see where various planes/nets are tied together.


                I would say post it on the Mentor Ideas site, but since they are not updating the "best" list (the top ten ideas all date from early 2008; ie.The earliest ideas have the most votes', Surpirse, surprise!) I suspect adding anything new to the ideas site is an exercise in futility.

                • 5. Re: Star Points - Do you need them?

                  Have you used the embedded resistor component?  You should be able to place it on any layer in the PCB design.  I don't know if this is available on all levels of Expedition, Ascent - Pinnicle, but I think that it is.  You will merge the resistive shape with the copper when you produce photoplotter files.

                  • 6. Re: Star Points - Do you need them?

                    The Ideas site has its own blog and the decision process is described here:



                    • 7. Re: Star Points - Do you need them?

                      Thanks for the link, Richard. However, it seems that my intial assesssment was accurate - Only the most popular ideas will be looked at, and by definition, the most recent, adn most popular ideas will attract the vast majority of new votes - THey will not look at page "97" which may well contain a brilliant idea.


                      The Mentor ideas initiative is fundamentally flawed. It has nothing to do with the quality of ideas but the popularity, and whilst the two are not mutually exclusive, they certainly do not automatically go hand in hand.





                      • 8. Re: Star Points - Do you need them?

                        Yes I do,  I create a foot print with pads overlapping and find it a real pain when checking, so many errors.  Come on mentor give us what we want.

                        • 9. Re: Star Points - Do you need them?

                          Yes, I need star points!


                          I just followed the link and logged on again. It's been a while since I was last there, but I submitted several requests for things including star points and the ability to flood over pin thermals for high-current, high-disipation parts. I also voted on a number of things.


                          According to Mentor, I've submitted zero ideas and given zero votes of support.


                          So .. Like talking to a brick wall!


                          I'll definitely not now see it as I've terminated my support contract.



                          • 10. Re: Star Points - Do you need them?

                            Ah .. though in fairness, that's an Expedition blog and I'd have submitted on a Dx/PADS blog.

                            • 11. Re: Star Points - Do you need them?

                              I had a simular case, where a in-board coil was needed. just some routed wire on inner layer, but with symbols on schematic.simular to star point.

                              could not create it as a part, so had to do it as dummy symbol in schematics, with single pin to get the holes over to expedition.

                              DRC and ODB++ errors were one of the reasons, not to define copper traces in the cell.

                              In schematics you want to give the special connection a specific place, to seperate parts connected to one side, and those connected to the other side.

                              Maybe Mentor wants to get this in the pin-order settings, but to me that seems to far in the process. How difficult can it be, some sort of net extension,

                              that seperates the connections, but creates an single net for

                              ODB and DRC....


                              Yes we do need this.

                              • 12. Re: Star Points - Do you need them?

                                Yes, we need Star points.

                                • 13. Re: Star Points - Do you need them?
                                  Wim Creyghton

                                  A very serious YES!!!!

                                  Now we are using a buried resistor shape with shortened pin 1 and 2 with an conductive shape.

                                  This only works for 2 nets.

                                  I've you got more nets, you get more buried resistors.

                                  This problem can be solved with one starpoint.

                                  • 14. Re: Star Points - Do you need them?

                                    We use Star Points all the time.


                                    Zuken's CR-5000 can do star-points (or star vias as we call them).  We need this capability for Expedition.  Come on Mentor, how come your competitor's software has a feature that Expedition does not.  Don't you want to stay competitive?



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