errors from the area checked must use the same area as is used
by the interaction checker to recompute errors. In earlier code,
both these areas were much larger than necessary. In the last
code update, the area to make revised checks was reduced, but
the area cleared of errors was not, resulting in errors that
would disappear from the layout as paint changes were made, until
a full "drc check" was run again. This code commit makes the
areas the same again so that no errors are lost.
much larger area than necessary to the interaction check, and
the other which failed to scale the tech halo distance down
after scaling all the rules. Both of these led to huge areas
of a layout being unnecessarily checked when even a tiny part
of the layout was modified. Corrected behavior matches
expectations for interactive DRC response.
to have come from an unfinished (or at least unchecked) development
effort on improving the checks for DRC interaction errors (which
also affects extraction).
avoid the problem where subcells violate DRC themselves but do
not violate DRC in the context of the parent (i.e., the parent
adds metal to avoid minimum area error), DRC errors in subcells
are neither counted nor displayed, but they remain present in
the subcell database. The DRC check enumerates all subcell
errors as mandatory check areas in DRCFindInteractions(), so
that those areas are always counted with the interaction areas.
Previously, if a subcell violated a DRC rule by itself, that
error would be counted and displayed in the parent even if the
parent had paint causing the error to no longer exist.
Tim Edwards