true, this will force the "gds write" command to write out creation
date stamps as zero. This is very useful for avoiding changing the
contents of an otherwise-unchanged layout, especially if it is in
a git repository where it will force the entire file to be replaced.
hierarchical processing from CIFGenSubcells() and CIFGenArrays(), and to
avoid certain operators that are useless and harmful when applied
hierarchically; namely squares, slots, bbox, boundary, and net.
templayers. This permits some useful interactions like growing to
the size of a bounding box, or abutment box, as well as many other
possibilities. Also: Corrected the use of "cif see" for the boundary
(abutment box) layer, which was not working because the "cif see"
command uses a flattened CellDef that does not have the boundary
property of the cell it was flattened from.
GDS of abstract views, such that if the cellname being dumped is the
same as the library name, then no prefix is added to subcells. This
behavior may be changed in the future.
only at the time of running the command "load". But cells are generally
loaded only on an as-needed basis, so the dereferencing option must be
saved as a flag in the cell and honored whenever its subcells are expanded
or otherwise read at a later time.
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.
rid of redundant port entries in subcircuits. There is still an outstanding
issue as to whether nodes and connections need to be recursively iterated
to the hierarchy bottom. The current fix corrected the test case. Also,
added a "-dereference" option to the "load" command to revert to the
original behavior of using only search paths from "addpath" when searching
for files to load.
the forward-referenced GDS cell problem) in which when writing cells
from 3rd-party GDS, the structure names are written to GDS with the
indicator flag in front, making the structure names and the referenced
names different, so that the GDS file is no longer valid. This has
been fixed.
files that have forward references (cells that are instanced before
they are defined), resulting in those cells being given an undefined
string for a prefix, which will result in corrupted GDS output.
Also added a method to prevent forward-referenced cells from triggering
a "redundantly defined" error message when the structure is output.
the compiler. Some are obscure functions (plot verstatec hasn't
been used in years) but others (like SPICE distributed junctions)
are potentially significant sources of unexpected crashes on
systems that don't zero uninitialized memory.
lengths exceeding the maximum GDS name length (32 characters),
truncate by removing all but the last 32 characters, instead of
the previous behavior which was to remove all but the first 32
characters. The last 32 characters are far more likely to be
unique than the first 32, given that the usual reason for extra-
long names is the concatentation of hierarchical names.
the output to have an obstruction area over the entire cell except
for a keep-out area around each pin. Instead of marking every
part of the pin geometry, only the "chunk" (largest immediate
rectangle) surrounding the port label is output as part of port
LEF geometry. This avoids making unnecessarily complicated
abstract views, and makes it easier for other tools to read and
manage the same abstract views.
to prefix all library components read from GDS files pointed to by
an abstract view (other than the cell itself) with a prefix. But
this does not account for the fact that the same library may be read
by other cells. The solution is for every cell in the library, check
if there is a cell in magic with the same name which is also an abstract
view that points to the same GDS library. Those cells do not get
prefixes. At the same time, however, it was discovered that the GDS
cellname character limit is set at 32, and so prefixes must be kept
short. To keep the prefixes unique, the prefix was changed to a 4
character random alphanumeric sequence, and a warning is issued if
any GDS cell exceeds the 32 character limit.
"port" and "noport" in the cifoutput section to distinguish
between layer:purpose pairs for port text vs. other kinds of
text. This allows a closer correspondence between GDS read and
write. Note that the port writing is currently only in the GDS
write routine, not in the CIF routine.
additional functionality for ports in GDS format. This has been
tested with a techfile encoding pin types on a different purpose
than the metal layer drawing purpose. The label rectangle is
correctly written to the GDS output as geometry on the pin
purpose layer, and the same layer gets read back in from the GDS
file and translated back into the label rectangle. Port order
is maintained.
geometry attached to a label in GDS using specific layer:purpose
pairs. The additional code maintains the order of ports when
writing out text to GDS, and attempts to attach geometry to labels
when the geometry is defined on the same layer:purpose pair as
the text, and the cifinput style declares the purpose to be a
port label.
an error message when reading uses from a .mag file. Also modified
the GDS write routine to provide an error message when an abstract
view points to a GDS file but the GDS file cannot be found.
both an abstract view (i.e., comes from a LEF file or otherwise
has been marked with the LEFview property) and a GDS_FILE
property expects to insert the contents of GDS_FILE into the GDS
output stream minus header and trailer, and with all internal
cells renamed by prefixing them with the top-level cell name to
avoid naming conflicts.
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