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another off-grid problem (pathSeg cannot be rounded to grid)

tdtg

Here is another pesky offgrid problem. We have a design where unfortunately an instance was placed somehow by a Layout XL bug in offgrid location. Then a bunch of wiring was done with wiring and bus tools to this instance. As a result there are hundreds of wires consisting of pathSeq that are now offgrid. The vendor requires things be on 0.005um grid and these have 0.001um offgrid placements.

Now the skil script CCSputOnGridHier() will fix many of these. But we have pathSeq that cannot be fixed. We cannot even fix the offgrid manually using the property editor. If we try to adjust this vertex .691 to match the .69 Begin Point vertex, the CIW prints

*WARNING* (DB-270000): dbSetPathSegPoints: Begin and end points do not specify a horizontal, vertical, or diagonal pathSeg.

Is it because the wire is part of a bus or is somehow constrained?

This is an awful problem since we are faced with hundreds of these stupid offgrid violations and this stuff always happens right before tapeout deadline.

We would really appreciate some advice on how to proceed besides redrawing all these wires from scratch.

Thank you!

Tobi

Parents

  • More about this, the script actually does something really unexpected and bad IMO, it sets the pathSeg extension to zero, so that a wire pathSeg that starts out like this, note the extension of 3.4um

    turns into this

    Note extension is now zero

    We don't know what do do about this. 

  • in reply to tdtg

    Would it be possible to suggest a fix to this part of code so that it modifies the existing pathSeg to make sure all properties are preserved?

    here is the code in text

    ("pathSeg"

    pathSegId=dbCreatePathSeg(cv obj~>lpp car(path) car(last(path)) obj~>width obj~>beginStyle obj~>endStyle)

    if(obj~>figGroup then dbAddFigToFigGroup(obj~>figGroup pathSegId))

    geSelectObject(pathSegId)

    dbDeleteObject(obj)

    ) ;pathSeg

  • in reply to tdtg

    Probably it would be enough if the script would round the pathSeg extension values to the grid as well as the vertices

Reply Children
  • in reply to tdtg

    I would suggest that you either create a case via support.cadence.com or give feedback on the article you reference; that's the best way of it getting back to the article author (it's not me...)

    I would also wonder why you are getting the off-grid points in the first place; that's very odd, given that pathSegs are constrained to be octilinear. You might want to raise a case for that alone.

    Andrew

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