1 Reply Latest reply on Nov 27, 2017 8:37 AM by Patrick.Cashman

    Automatic schematic connection of GND and POWER pins on large pin-count devices


      I'm thinking of writing a VB script that will automatically connect (common) on the schematic all GND pins and the various POWER pins for large pin-count FPGAs.


      Some of the latest devices have several hundred power pins


      Has anyone written or attempted such a script?

        • 1. Re: Automatic schematic connection of GND and POWER pins on large pin-count devices

          This is possible.  The key element is placing the power/ground symbols on the schematic sheet.  Here is an example script:


          Sub add_power_tap_symbol()

                   Dim view As ViewDraw.View

                   Dim blok As ViewDraw.Block

                   Dim comp As ViewDraw.Component

                   Dim partition, symbol As String

                   Dim x, y As Double


                   view = app.ActiveView

                   blok = view.Block

                   partition = "Pwr_Misc"

                   symbol = "AGND"

                   x = 100

                   y = 100

                   comp = blok.AddSymbolInstance(partition, symbol, x, y)

          End Sub

          The script assumes that you already have a reference to an open DxDesigner session with the global app variable. 


          To make this into a useful application, there are a number of things to consider.  Here are some that come to mind:


          - Will the application run blind or with an interface?

          - Will the user select a component and then run the tool, or else how will the application know what part to work on?

          - How will the tool know how to identify the power and ground pins on the component? Pin names?  User selection in an interactive mode?

          - What kind of paradigm will you use to place the symbols?  Gang many pins together and connect to a single power symbol, or place one power symbol per pin?


          The two major areas of concern for such an application are:


          1. How will you know what power/ground symbol a pin will be connected to?

          2. How will you know how/where to place the wires and symbols on your schematic sheet?



          I'm not really asking you to answer these questions.  Only suggesting that in your application you will need to consider how to handle them in a large number of possible use cases. It's not an insurmountable problem but one that will take some care and forethought to implement effectively.