reduce the amount of redundant painting done by the connectivity
search algorithm, but which was preventing composed types (such
as FET gates) from getting added to a net if one of the composing
types (such as poly) was drawn over the device in an ancestor
cell. Removing the "if" statement does not appear to have any
significant performance impact, so this change is being adopted.
argument. For interactive magic in the Tcl/Tk wrapper, the
"-nowindow" option was appended to the command line. But for
Tcl scripts on the command line, all arguments following the
script name are considered arguments of the script. So the
"-nowindow" argument has to be inserted at the beginning of
the command line as the first argument after "magic".
previously, MASTERSLICE layers would not be added to obstruction
layers made by "-hide". However, an nwell, for example, that
stuck outside of a prBoundary *would* be recorded, which was
inconsistent. Resolved this by allowing MASTERSLICE layers
in the OBS block, but only for layers that are not a substrate
type. NOTE: It may be better to just insist that a MASTERSLICE
layer define an obstruction type in the "lef" section of the
tech file, and treat it like routing obstructions. Alternatively,
one may question whether special obstruction types are needed at
all, as one could simply define an obstruction as a type without
a port label.
contains brackets which are not indicating a cell array. Also
fixed a related issue with the PDK toolkit code, in which the
gencell routines fail if an instance name contains brackets which
are not indicating a cell array.
present. Note, however, this fix breaks the use of "ext2spice
subcircuit descend off" because subcircuits are always descended
into. It's not clear that "subcircuit descend off" worked at all
before, anyway. That still needs fixing.
non-default rule. The code was first failing to identify the via
cut type from the generated via record, and then it was failing
to return to the non-default rule width after the route exits the
via. Both issues have been fixed. Thanks to Sylvain Munaut for
providing a reproducible test case.
new port labels are created for an existing port, then they must
take the existing port number. The code was previously causing
collisions between port numbers on different pins.
lefLayer's "via" record even when the layer might not be a via,
causing potential issues with uninitialized variables. Not sure
if this is related to the bug that started this investigation,
but it was the only thing that looked relevant.
used in a re-entrant manner. Applied to an existing layout,
it will no longer keep generating new instances and ports over
top existing ones. Could use improvement by attempting to
retain the location of a device when the instance changes
device type (such as when a device parameter was changed in
the netlist). However, the current set of changes should
help, whether the re-entrant use is purposeful or accidental.
fails in the bplane code for subcell binning. It is still not
clear why this example causes a failure when the bplane code
has been working for so long. However, simply checking for the
BT_ARRAY bit at one additional point in the code prevents the
crash condition and appears not to have caused any issue with
the database.
a method that failed to work on devices with complex shapes on the
device recognition layer, such as snake-geometry resistors. (2)
The use of contact type "xpc" in the sky130 tech file as its own
contact residue caused the contact tracing in extresist to fail.
I opted to keep the unorthodox contact description in the tech
file and wrote an extension to a routine in extresist to handle
the case.
from Ryan Schmidt, changing regular expression strings in the python
preprocessor to raw string types so that they don't produce warnings
in python 3.12.
name. The instance search routine was not rejecting internal cells,
and so would choose, e.g., a selection cell and reject it because it
was not the edit cell.
The fractional part of the rule distance (modulus after scaling)
does not fit in the unsigned char variable unless it is first
divided by the scalefactor (also requires multiplying up by the same
amount when scaling the other direction). The truncation of the
unsigned char value was causing the minimum area value to be off by
a small amount, causing false negatives (no DRC violation is shown
when metal area is slightly smaller than the minimum allowed).
that resolves issues of excessive tile fracturing during read-in
of GDS (or CIF) polygons and paths that have non-manhattan geometry.
This was particularly noticeable when reading the GF180MCU corner
I/O cell, which ended up being something close to a worst-case
scenario.
missing from a netlist generated by ext2spice with the "extresist"
option enabled. The first had to do with some parts of nets being
given alias names for a net, and the second was caused during
"extresist" and would also result in error messages about devices
missing terminals.
"gds readonly true" mode and when writing a GDS file in full-dump
mode. Reading or writing a file with an incompatible DBU is now
prohibited. This is not a great solution, as it forces the
original file to be rewritten with a different DBU. Preferably
there should be code to scale the units during a dump, but that
needs to be coded.
correctly handle subcircuits that are used before they are
defined, and will determine whether the imported spice does or
does not contain a top level, and either return to the top level
or any top level cell found in the netlist.
client data value as the exit status value (this was not at
all clear from the documentation and required a bit of
experimentation). The fix allows Tcl scripts to exit magic
with a non-zero status by invoking "exit" in Tcl.
depending on the order of extraction devices. Specifically, the
case of a source-drain tied FET was breaking out of a loop when
it should have been breaking out of a double loop.
cell being generated. This statement does not disambiguate the
case where a cell is being ripped verbatim from GDS instead of
being generated from the magic database. This print statement
has been split into two cases, and where a cell is being ripped
verbatim, the name of the file is indicated. This provides better
information to the user.
no way to implement boolean operators on labels, so any "label"
statement in the section can apply only to one magic layer. This
is regularly violated in most (all?) techfiles (due mainly to lack
of explanation and guidance). The addition of the "no-reconnect-
labels" option for cifinput made it worse, as it can cause a label
to be attached to the wrong layer and be stuck that way. Even
without the option, an attachment to a non-connecting type is a
problem; DIFF cannot simultaneously have a connection to both
ndiff and pdiff, so it will be one or the other, and the one not
connected can easily get labels moved to other nets. To avoid
this: (1) removed the "no-reconnect-labels" option, and (2) made
the automatic label reconnection smarter, as well as splitting it
into two different behaviors based on whether a label is being
created or manipulated from the command line (more or less the
original behavior) vs. being read from GDS or LEF. The new rules
assume that labels attached to a GDS type will all map to the
same plane in magic. To avoid excessive error messages from
existing tech files, a warning is issued only if "labels" changes
the plane of the target layer (a realistic solution rather than
the preferred one). Also: Fixed an error that causes a crash on
the "wizard" command "*watch" if the cell being observed is
read-only (see github issue #271).
"unexpected asymmetric device" is printed prematurely, as it
is inside a loop checking over all device entries compatible
with a device type. Also: Flagged an issue with the "label"
keyword in the "cifinput" section of a tech file. The "label"
keyword cannot be used in conjunction with boolean operators.
It can only connect labels on a specific GDS type to one magic
type. Unfortunately, because this was not flagged before as
an error or warning, the incorrect usage has crept into a lot
of tech files. This uncovers an underlying issue that labels
must be allowed to automatically reconnect types, which is
undermined by the "no-reconnect-labels" cifinput option. That
issue will be addressed in an upcoming commit.
to pick up properties from an existing cell and prints an error
message instead. This will likely cause non-default properties
of an instance to be lost if the SPICE import is used in a
re-entrant manner (not exactly a common use-case).
was made to limit the ExtFindRegions() search to one plane per
contact. Fixed this simply by doubling the resistance per via
so that the final result is correct.
bounds should be called whenever an entry is changed and either
the entry window loses focus or the <Enter> key is pressed.
This had ended up disabled when the scrollbar was added to the
dialog window, causing the window hierarchy to change, which
invalidated the regexp used to identify the entry and checkbox
widgets.
cuts per contact area during parasitic resistance extraction.
Previously, the result was divided by the via pitch twice,
resulting in most contact areas being reported as a single
cut.
in DEF read and write. The NONDEFAULT LAYER WIREEXT was assumed
to refer to the default wire extension at segments, when instead
it refers to the wire extension only at vias. The wire
extension at segments is presumably defined by the nondefault
segment (and wire extension at vias remains unimplemented, which
is probably not a big issue because everyone puts the wire
extensions into the via definitions anyway).
all of its time running area searches on zero-area rectangles,
which was causing simple extractions to run hours. Checking for
a zero area rectangle and conditionally skipping the area search
resulted in a massive speed-up in parasitic extraction.
because commands issued during initialization set the DRC status
in a way that causes DRCContinuous() to return immediately.
Also: Implemented a slightly different method when automatically
finding the tech file from the input .mag file that loads a
technology .magicrc file if one exists. If not, just the .tech
file is loaded. This replaces the method of a previous commit
that loads the technology .tcl script. The .magicrc file will
include the .tcl script but does other things as well.
the time the option was implemented), and also implemented (and
documented!) a similar command option "extract stepsize" for
reporting or changing the extraction step size.
out where to find the technology corresponding to a file given on
the command line: (1) Changed the default search location from
/usr/share/pdk to /usr/local/share/pdk, which is the actual default
for open_pdks (can still be overridden by environment variable
PDK_ROOT). (2) Made the PDK name by itself preferable to the PDK
name plus any extension when searching (e.g., "sky130A" is preferred
over "sky130A_backup"). (3) Check the located directory for any
file <tech_name>.tcl and source it if it exists. (4) Run any tag
callbacks on the "tech load" command, which rebuilds the tool icons.
when a label has no area and magic has to go searching for the
label area. The resulting behavior is better but is not really
a substitute for adding ports on the proper layers in the proper
locations for routing connections.
(fixes some issues around python3 on the Mac, python3 conflicting
with that found by /usr/bin/env, and an issue around "make clean"
attempting to rebuild the Depend files).
engine. Rule checks of triggering rules are not subject to
clipping to the clip area. However, they *must* be clipped to
the (larger) overall DRC check area, because no layout is valid
outside of that area. This clipping was missed, allowing
triggering rules to trigger on areas outside the valid layout,
resulting in mysterious false-positive DRC errors. This has
been fixed.
Tim Edwards