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Need to get the minimum spacing on board file.

eDaNoy

Problem to solve:

I need to return the smallest gap distance on board file.

Need to compare all objects like pins, vias, clines and other Segs to each other. 

I already had the program but I'm having an issue with its performance.

It was slow.

Does anyone here can share some tips, suggestions or program sample.

  • This would be extremely slow if you tried to compare every object with every other object.

    Just measure between each object and objects you find within a limited bounding box area of it using axlAddSelectBox. You can reduce the size of the bounding box each iteration as you find a smaller minimum gap. Of course, if you hit zero, you can stop!

  • If using 16.6, you can try a divide and conquer approach by using the min-metal DRC check. Basically, enable it and set a value. Run drc update and see if you got any min metal DRC. If you give it a reasonable small value (but not the min database accuracy) you can do it in one pass.

    For the one pass approach check all of the resulting min metal DRCs and compare their actual vs constraint values. The smallest difference plus your min metal value is your minimum gap value.

    This strategy only applies to objects on different nets. If you are interested in same net min spacing then you will need another approach.

  • Hi Dave, the current program works like what you said. I just don't like it's performance. Anyway thanks for the advice. I appreciate it.
  • fxffxf, I was thinking already this kind of approach also. But Run DRC Update is also time consuming especially when you are checking big boards like server projects. If there is a way to make DRC update faster then maybe it's the right thing to do.

  • Turning off all other DRC checks while doing this check will make it faster also since the DRC update command can take advantage of multiple CPUs

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