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How to place an instance regardless of its SITE definition

jgentry

All,

  I have some instances that need to be rotated 90-degrees from their "normal" orientation.  However, when I try to placeInstance, dbPlaceInst and even set R90 from the attributes menu, it always tells me that it is reseting to R0 because the desired orient, R90, doesn't match the CORE site definition (the SYMMETRY line in the LEF is 'X Y R90' and, thus, isn't preventing the rotation itself).  Is there a way around this other than to create some DEF with the desired inst locations and R90 orients (which works by the way)?  

Thanks,
JG

Parents

  •  Kari,

      Yes, it is a stdcell.  It's a filler cell actually.  We have sections in our chip where we put in a clean supply grid but it has to route orthogonal to the normal core power grid in order to provide adequate shielding for reference clock routes.  I was hoping there was some switch somewhere to tell the *place* commands to just do it (I was hopeful that dbPlaceInst was the command that would ignore any site definitions).

     

    Thanks,
    JG

Reply

  •  Kari,

      Yes, it is a stdcell.  It's a filler cell actually.  We have sections in our chip where we put in a clean supply grid but it has to route orthogonal to the normal core power grid in order to provide adequate shielding for reference clock routes.  I was hoping there was some switch somewhere to tell the *place* commands to just do it (I was hopeful that dbPlaceInst was the command that would ignore any site definitions).

     

    Thanks,
    JG

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