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Cannot swap pins across fractured symbols - This is not a good thing!

Question asked by SHWTIME7 on May 26, 2010
Latest reply on Oct 22, 2018 by Gary_Lameris

This is more of a statement of concern/frustration. But, at the end of this I would like to know if there are other companies having the same issues and if so what have they come up with as a work around.


I have been developing our PDB's to include pin swapping in Library Manager. So, when we get to the PCB level, the PCB Designer can swap all the defined pins and then back annotate into DxD thus allowing us to keep the schematic flow intact. Also, this will give the PCB designer much more flexibility on his end rather than force feeding those swaps via the schematic, which adds more time and well you, know the rest.


I have seen a lot of companies create PDB’s with very little parametric data and pin swap capability, either because they have not taken or had the time to develop their libraries appropriately or maybe they just didn’t know how. Now, I am not saying that it is right or wrong, just that some initial planning and preparation can really stream line your process and make life easier on your designer and the team when being task to complete a rather dense design that may also be layer strapped and schedule crunched.


Anyway, we have a semi-high pin count BGA - 780 pins and within that part there are 12 fractures which will allow us to have a cleaner much more functional schematic. Unfortunately the way the tools work we cannot swap pins across the fractures only pin to pin within the same fracture. NOT GOOD!


I know some will say use I/O designer and this will take care of your issues. I disagree, what if I/O designer is not an option and in our case it is the latter. What would be the work around? Sounds to me that creating a very basic or generic library with very little structure or dynamics is the way to go, which means staying away from fractures and creating one massive symbol which we all know is not a good approach.


There should be a process or an avenue that will allow the same type of functionality on a general level that I/O designer offers. At least to the level in the PDB structure via Library Manager which will allow fracture to fracture swap capability?


I submitted and SR and talked with some of the AE’s at Mentor about this issue and there response was..."this is a limitation in the tools”. Now, I am not sure if they are planning to develop an alternative to I/O designer (within Library Manager) or if they’re going to push I/O designer. I am going to lean towards the latter on this one.


Any thoughts or comments?