Non-Manhattan, all angle, or 45 degree shapes in Calibre xRC

Document created by rick_sedlak on Sep 17, 2012
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When using data having all angle geometries with Calibre xRC versions 2007.x through 2010.1,
the Calibre xRC PDB step may fail in one of the following ways:

   The run may hang
   The process may get aborted
   A segmentation fault may occur

Regarding design data containing geometries with angles that are not 90 degrees, this type of data is also called 'all-angle' or 'non-manhattan' layout data.  

45 degree layout design data will also cause this problem behavior.
If the non 90 degree data is in the form of metal fill, it will also cause this problem behavior.

Please Note: This is problem is fixed in the 2010.2 and newer Calibre product releases.  This remains a known problem in the tool for Calibre xRC versions 2007.x through 2010.1.


For all angle data processing  by Calibre xRC, use v2010.2  or newer releases.

If you must use
Calibre xRC versions 2007.x through 2010.1:

[1] Avoid the use of 45 degree angled data, or any non-manhattan i.e. all-a
ngle geometries in the design.
Replace them with shapes having only 90 degree angles i.e. manahattan geometries.

[2] If it's not possible to remove these shapes, define these shapes within xcells and avoid extracting parasitics for them by running the gate level PEX flow:

      calibre -xrc -pdb -xcell xcell_file rules

For more on the gate level PEX flow consult the Calibre xRC User's Manual in the section titled: Running Gate-Level Extraction