one is an "off_grid" DRC type, which can be used to check geometry
that is below the manufacturing grid. Normally magic prevents the
grid from being subdivided below the manufacturing grid, but this
limit can be removed and replaced by DRC checks to check for such
errors in a GDS file of unknown origin. The second version looks
for interactions between subcells that end up with intersections
of non-manhattan geometry landing on points that are not on the
database internal grid. Such errors cannot be seen by magic's DRC
engine by definition, and so must be detected while flattening
geometry for the DRC checks.
the handling of subcell instances generally. Previously it would check
the interaction between neighboring cells in an array without regard to
any material in the parent cell which might remove those errors;
consequently, the array would have to be DRC clean by itself in order for
the parent cell to show as DRC clean. The array check has been moved
inside the DRCInteractionCheck() routine, so that it runs only where
arrayed instances do not interact with anything else. Within interaction
areas, the area is flattened and checked, so the array check is not
needed.
processes "interaction areas". This should eliminate weirdnesses
where errors will fail to show up in a subcell that does not
interact with paint or other subcells in the top level edit cell.
These errors cannot be reported directly in the top level cell,
but a new error message has been created to direct the user to
check the subcell for errors. Also: Modified the toolkit procedures
to force DRC to be run on newly created or modified parameterized
cell layouts. There is some oddity about the process that causes
DRC errors to be delayed unless a print statement is put before the
DRC check; I would like to investigate this further.
the rule is a normal database rule or a CIF-DRC rule. For the latter,
the flag is used when substituting for escape strings in the "why"
rule explanation to produce the correct value in microns.
DRC records contain an index into a string array instead of containing
a copy of a string. This is preliminary to changing the way the DRC
error plane is painted, so that the types painted will mark the error
type. This will (1) allow "drc why" to simply scan the DRC error
plane rather than running the DRC engine, (2) allow DRC errors to be
counted by area rather than by tile, and (3) let the DRC count be the
same whether done by "drc listall why" or "drc count".
to be investigated here. I am no longer sure why I removed the
cell search from DRC count, but it appears that the cell search is
non-functional, and it should be determined why. There is no
particular reason not to have a DRC count search. It could be
implemented such that "list" vs. "listall" counts the top cell vs.
all cells. First it must be determined why there are no subcell
counts.
categorized by error type and scrolled through conveniently. However,
it needs work dealing with finding the actual error bounds. The
"DRC count" counts tiles, which is tile-plane-geometry-specific, and
"DRC listall why" fractures errors both over tiles and over the square
areas that the interactive DRC splits the layout into, for performance.
The DRC error plane needs to be changed to hold different types for
each error class, so that errors can be scanned by boundary instead of
by tile (work to be done).
behaviors: (1) An additional syntax for "widespacing" that allows
both the triggering metal's width AND run-length, which is typical
of rules in 65nm-and-below processes; and (2) a new "option"
statement for the DRC section, with (for now) one possible flag
"wide-width-noninclusive", indicating that the metal width given
for "widespacing" rules means that a violation is only triggered
for material with a width greater than the given rule width (as
opposed to the default interpretation of a width greater than
or equal to the given rule width).
Tim Edwards