attempt is made to write an abstract view to GDS. This behavior can
be overridded with the new command option "gds abstract [enable|disable]".
Also: Corrected extraction to allow split tiles to be set as the
reference tile for a node. Previously this was allowed only if the
tile was the first to be searched, but that can cause different tiles to
be marked as the reference depending on where the search starts,
resulting in different names for the same node in .ext files, which is
bad. Also: Modified the LEF annotation to avoid bad entries in the LEF
that would create layers in the layout where none exist.
fact that "extract all" does not enumerate cells from bottom up
as I had assumed---The order is roughly bottom-to-top, but cells
re-used in different places in the hierarchy could end up called
before one or more of their own subcells is extracted. Since
this conflicted with the preparation of the substrate in each
extracted subcircuit, I changed the method to enumerate cells so
that it is properly bottom-to-top. Also, methods were added to
"extract" (incremental), "extract cell", and "extract parents"
to ensure that the substrate is prepared on all subcells before
extraction.
a routine that should have been called with a NULL argument, but
instead was called with no argument, making the behavior system-
dependent. Revised the parsing of the "defaultareacap" and
"defaultperimeter" statements in the tech file, such that the short
version of both statements gets automatic handling of the substrate
and isolated substrate areas; this goes back to the recent change
in extraction behavior to redefine the "substrate type" (e.g., pwell)
during extraction as defining isolated substrate areas, and not the
default substrate. The earlier code change dealt with problems
related to extracting nodes and regions, but did not consider how
parasitic capacitance was affected. This commit resolves that issue.
time ago by cleaning up excess usage of "equiv" lines in the .ext
file output. The hierarchical extraction code did not distinguish
between node names which were output and those that were not,
requiring a setting "extract do aliases" to force all node aliases
to be output with "equiv" statements. So hierarchical names
might be any alias, whether output or not, and "merge" and "cap"
lines might contain references to nodes that were not output,
causing them to be disconnected nodes. This fix handles the
"extract no aliases" (default) case by flagging node names that
are redundant and not output, and not creating hierarchical names
with them.
not restored until after all cells have been processed through
extraction. Otherwise, top-down connections can end up with
different generated names for the same node, resulting in a
disconnect in the netlist.
Tim Edwards