in which if a cell is read from GDS that has the same name as a cell
in memory, then the cell in memory is renamed to keep all cell names
unique in the database.
This can be done now by reading a LEF file, followed by reading
a GDS file with the "noduplicates" option set. In addition,
annotation of either the LEF view or a read-only view follows the
same protocol as cell paths in the .mag file, which is to replace
leading path components matching Tcl variables for PDKPATH or
PDKROOT, and replace the home directory path with a tilde.
flattened per "gds flatten" or "gds flatglob", and the "gds readonly"
option is not set, then the instances of the flattened cells are
removed from the layout. They are retained for the "readonly" option
because when writing GDS of such a cell, the full hierarchy needs to
be walked.
from slashes in hierarchical names. Magic does not allow slashes
in names when using "identify", so the simplest solution is just
to prohibit them in names being read from GDS files, and replace
them with underscores to make them magic-compatible. Changing
GDS names always has repercussions on things like back-annotating
delays, so it should probably be revisited in the future.
of input cells on a per-cellname basis, using glob-style pattern
matching. This is probably the best way to deal with 3rd-party vendor
GDS with unfortunate practices like dividing devices up among cells in
a hierarchy, even though it comes across as a bit of a hack solution.
routine attempts to rescale the contents of the top-level cell after
moving forward in the GDS to find a cell that was used before it was
defined, if reading that cell caused the scale to change. However,
the numerator and denominator were reversed, causing the scaling to
be the inverse of what it should have been.
to allow a "gds read" command to ignore cells in the GDS which already
exist in memory. This allows magic to be "pre-seeded" with specific
views of cells in the GDS. Default is false, which is backwards-
compatble behavior. (2) Changed the behavior of the the way the use
path is written to and read from a .mag file, checking the path prefix
against Tcl variables PDK_PATH, PDKPATH, PDK_ROOT, and PDKROOT, and
replacing any such leading path component with the variable name.
On reading a .mag file, any variable name at the start of the path
that matches a Tcl variable will be substituted.
used both for counting cells during GDS write and for saving
geometry data from the "copyup" operator during GDS read. The write
routine does not clear the client record, and the read routine was
checking if the cd_client value was default. Corrected the resulting
crash condition by resetting cd_client before GDS reads. However, the
underlying problem is that the GDS read is reading data into a cell
that already exists in the database, and is not handling it robustly
by renaming the existing cell. So this should be revisited.
substrate more than once for the same subcell, since the substrate
extraction method scans the entire plane area; this was making
large standard cell layouts extract very slowly, as every component
cell was causing the substrate search to be repeated.
limit of the Calma definition, and probably has not done so for ages.
Nobody informed me of this. The restriction has been lifted from
GDS input and output in Magic. It can be reinstated if necessary by
setting a flag in the cifoutput section of the techfile, but it is
likely that this will not be necessary unless there are other tools
that enforce the limit and will not read a GDS file that exceeds it.
item that was never properly validated. Corrected the root of the
problem, which was an attempt to deallocate memory that had never
been allocated in the first place.
development had been halted since it was first created back in April.
Version 8.2 is now the official development version, with the first
development push to create a Cairo graphics interface.
Tim Edwards