"lasttop" after a new heap has been allocated and "top" is reset.
This is a minor issue, as even random data at the top of the
newly allocated heap is vanishingly unlikely to make a match,
but valgrind caught it as a use of unallocated memory, and it
should be fixed.
determining what does and doesn't get into the R-C extraction
output. Added option "debug" and moved all excess diagnostic
information to be gated by this flag. Corrected an issue in
the standard extraction in which the substrate is always output
with zero lumped resistance, preventing it from being checked
by "extresist" for inclusion or exclusion in the .res.ext output.
Reinstated the computation of minimum resistance transistor but
excluded other devices. Added more sane handling of exceptional
conditions like loops. The result is a more consistent check of
nets in the design. However, I still need to recheck the
"rg_maxres" calculation because it appears to be too low.
that "extresist" selects or rejects networks for resistance
extraction. The "tolerance" value, which nobody (including
myself) seems to understand, is now deprecated, replaced by
a handful of more meaningful options: "threshold" to set a
lumped resistance estimate threshold to determined whether or
not to extract a network; "minres" to specify when to prune
small resistors from the resulting tree network, and "mindelay"
to gate the selection and output on the estimated signal
propagation delay. With these settings, I am much better able
to control the size and complexity of the resulting output.
overhaul was to introduce the concept of a "connection point"
between two cells to the ".ext" file format so that it becomes
possible to do proper hierarchical R-C extraction. Previously
this information was not kept in the .ext file, making it
impossible for "extresist" to know what sub-net of a net connects
up or down the hierarchy. However, additional changes were made
to the extresist code (in the resis/ directory) to add the
handling of connections up and down the hierarchy, and to make
the code a lot clearer and fix ambiguous variable and subroutine
names.
The original version of extresist only worked with 4-terminal FET
devices, and handling of devices with fewer terminals was ignored,
and never properly dealt with. This commit fixes the issues with
devices such as diodes that have fewer terminals.
with respect to visible/invisible labels and cells. The change
inadvertently made the "select area" command option stop selecting
labels on the same type as the layers being selected. This has
been fixed.
this had two issues: (1) "getcell" was not being called with
"child 0 0", leading to child cells that are not placed where
expected in relation to a grid snap setting; and (2) "cursor"
was assuming internal units and needed that to be explicitly
stated using "cursor internal".
DBPaint() and DBErase(), which are meant as high-level calls from
the "paint" and "erase" commands and are not appropriate for low-
level tasks like erasing all contacts out of a database. This
cut maybe 40 to 50% time off of the resistance extraction.
avoid re-parsing a linked list from the current breakpoint
to the end to find all entries pointing to the same node.
Instead, the change to be made is saved in a hash table and
applied at the following link, so only one pass through the
linked list is required.
Changed the "ResDissolveContacts()" routine to avoid running both
redundant and useless code. Changed the breakpoint sorting
routine from a bubble sort to a merge sort for linked lists
longer than 16, as merge sort is more efficient for long lists.
line parser does not recognize arguments that are both in the
same word and also space separated; this is easy to do from, e.g.,
a python interpreter by setting an option as a single string as
in "-d null"; it is harder to do from the command line, but can
be done with quotes, as in 'magic "-d null"'.
The utils/args.c routine parses this with ArgStr(), which recognizes
two cases, one in which the option is split across two arguments,
and one in which the option is one word without space separation.
I modified ArgStr() to accept a third syntax in which the option
is in a single argument but is also space-separated. This simply
detects a space in the third character position and moves forward
to the next non-space character and returns that position.
the repo parsing on opencircuitdesign.com, since yesterday I found
out that the tags were not updating, caused by a documentation
change in a copy of the repository that created a merge conflict
when seen by the script. Will check tomorrow that everything ran
smoothly overnight.
DEV_RSUBCKT as well as (previously implemented) DEV_RES. The
handling of DEV_RSUBCKT includes checking if the subcircuit has
a substrate pin, and zeroing the capacitance to substrate for the
resistor node, under the assumption that the parasitics are part of
the resistor subcircuit model.
due to moving away from using the node "location" in favor of a
drivepoint specified by a port or other connection point. The
"location" record can end up at the default value of "infinity",
and should not be used to set the area for searches. This fix
is in response to issue #502 on the github issue tracker, submitted
by Julian Schwarz.
code now for 10 days). The last commit fixed an error when using
drcCanonicalMaxwidth() multiple times in DRC rule checks on a single
edge. At the time, I also added a method to save some
drcCanonicalMaxwidth() results to prevent needlessly re-doing the
same (potentially expensive) computation over and over. However,
where I reused the cached result, I did not check if the number of
entries is zero. Other code does not check the number of entries
and depends on the prior behavior that drcCanonicalMaxwidth()
returns NULL when there are no entries. So the code needed to check
if the number of entries is zero before re-using the cached result.
Without the fix, any time the caching is used, the last computed
maximum area rectangle will be made active even when the current
check area does not meet the area requirement, resulting in many
false positive errors.
routine, which in turn affects various DRC rules like maxrect,
widespacing, and runlength spacing. drcTile() was computing
the drcCanonicalMaxwidth() result for the tile and reusing it,
failing to account for the fact that within the loop over
DRCCookies, other rules might require calling drcCanonicalMaxwidth()
on a neighboring tile, or on the same tile with a different width
requirement. Implemented a cached version, in which three results
are kept: One for neighboring tiles (which can never be reused on
the same edge), one for the first required use of the routine for
the tile, and one for any other use required for the tile. If
there are one or two such rules for an edge, then the routine will
work at maximum efficiency. If there are three rules, then one
will always be a cache hit and reduce the total amount of
computation, although it will still be doing a massive amount of
redundant computation. If this seems to be something that
occurs regularly, then it can be revisited. The existing
implementation works fine for all the open PDKs. Some more
advanced PDKs with a number of staged wide-spacing rules could
have issues.
"tool" command was changed to be overridden by a Tcl command. Due
to macro clients being registered with the tool name instead of
just "layout", the "macro" command with no arguments or with a
window client argument was just broken. In the process of fixing
this, I realized that there was a conflict between the use of
"netlist" as a window name and also as the name of a tool, so I
changed the tool name to "nettool", a change which should be
transparent to the end user. Otherwise, "macro netlist" returns
the key bindings for the window, and the only way to get the key
bindings for the tool is to make the tool active and then use
"macro" without arguments. One remaining issue is that there is
no syntax error that will cause the list of valid windows and
tools to be printed. Probably "macro help" should print usage
information instead of acting like "macro" with no arguments.
operator does a second search to reset tiles and clear the
"processed" mark. This second search was only searching on the
types being bloated *into* and not the original types being
bloated. This caused tiles to remain marked as "processed" which
could in turn cause the tiles to be ignored forever after, potentially
resulting in bad GDS output.
by old code that still references devices like FETs assuming
four ports. I resolved the crash condition but have not worked
on fixing the code to properly handle a variable number of
terminals per device.
had numerous problems, the main one being that each of the three
commands was inconsistent: "expand toggle" inverts the expansion
of the selection and syncs with the layout. But "expand" expands
the layout where instances overlap the box and does not sync to
the selection, and "unexpand" unexpands the layout where the box
completely surrounds instances. Added a set of options to
"expand" and "unexpand" so that these functions can be made
consistent with each other. All varieties of the function now
always sync the selection and the layout.
back to the file, instead resulting in a property key only and no
value; this in turn produces an error when read back in. Another
cycle of reading and writing causes the property to disappear
altogether.
Also: Corrected another related error that claims to have truncated
the mask hints when in fact everything was working normally.
(1) There was still one place that dimensional units were not being
printed, which was "setlabel", with both "setlabel size" and
"setlabel offset". This has been fixed.
(2) Fixing (1) surfaced an error in the text helper dialog, which was
not setting units properly when checking the size and offset entries.
(3) Fixed a very long-standing problem in which port labels were showing
up with the "pale" style of a subcell's label being drawn on top
when the parent and child had the same label in exactly the same
position. This was due to a parent-first search resulting in the
child cell being visited last, so its "pale" style label being drawn
last. Added a flag for label searches for display to reverse the
search order, visiting children first and then the parent, so that
the top cell's labels are the last to be drawn.
and managed to commit some code that I thought I had tested---
but apparently what I tested was not the latest version of the
code. So 8.3.627 is quite broken and won't even compile. This
update fixes that.
exceptions; avoided the use of "signed char" altogether by just
making the drcc_exception value a bit mask with the lower 7 bits
being the index and the upper bit being the flag for exception (0)
vs. exemption (1), with the value 0xff being reserved for "none"
(no exception or exemption). This implementation should avoid any
issues caused by ambiguity in the use of signed vs. unsigned char.
the issue of a device name in a netlist having different case than
the procedures defined for the device in the PDK. The difference
in case is transparent to SPICE, so it should also be transparent
to the PDK.
allow ideal devices in an input netlist to be mapped to
automatically generated cells. This works if the PDK toolkit
defines a device called either "capacitor" or "resistor". The
device must be defined such that it can determine sane parameters
for the drawn device from only a value given in the netlist
(capacitance in farads, or resistance in ohms).
to avoid bogus values for array pitch in the direction in which
a cell is not arrayed: If the array declares an ANGLE of 90 or
270, then rows and columns are effectively swapped for the
purpose of figuring out which coordinate direction should be
ignored in the input. The original example did not use ANGLE
and so the exception was not handled.
ideal, unmodeled capacitors or resistors are missing a space
between the 2nd terminal and the device value in the output
netlist. This affects the ability to produce correct output
for, for example, a metal fingered capacitor using the
"device" property to generate an ideal capacitor in the
netlist.
to material in a child cell, and the label is a point or line label,
and the parent cell has no material other than the label in the
immediate area, then the "interaction area" will have zero area,
which will cause problems as area checks on a zero-sized area don't
do anything useful. The solution is to ensure that interaction areas
do not have zero area, but will expand around point labels. This
should not have any other implications, because the interaction area
is just a way to limit the amount of processing; larger interaction
areas do not affect the extraction result (except in this case, where
it fixes the error).
like "bloat-all" except starting with a label and expanding into a
type rather than starting with a layer. This is equivalent to what
many tools refer to as "stamping".
yet another property type "plane". This allows mask hints to be
handled like tile planes. That is, after all, what they represent.
Although this change is transparent to the end user (apart from a
slight performance improvement that is probably not noticeable), it
allows for a number of useful future extensions, including the
ability to handle non-Manhattan geometry in mask hints, and the
ability to view and edit mask hints like any other layout.
This features allows two new instructions in the tech file "drc"
section: "exception <name>|none" and "exemption <name>|none". The
purpose of these rules is to allow DRC rule exceptions for certain
areas which are marked, usually by a GDS identifier layer. Because
GDS identifier layers can be cast as "mask-hint" properties, the
DRC rule exceptions make use of that (recent) feature. So rules
can be specified as "exceptions" (rule applies for layout inside
the marked area) or "exemptions" (rule is ignored for layout inside
the marked area). Rules following the statements will have the
exception or exemption applied until another exception or exemption
statement is given. Either "exception none" or "exemption none" will
stop applying any rule exception or exemption. This is especially
useful for applications like SRAM where there may be a number of
rule exceptions on different layers. The previous way to handle
that was to create new layers in magic for any layer that needed a
rule exception. That mainly resulted in very messy tech files,
and a large number of defined layers. This implementation is both
simpler and cleaner.
and no ports are still supposed to be output as instances if they
have been marked as abstract views. Such views were getting output
as cell definitions but not instanced, which although is irrelevant
for simulation, would potentially cause LVS errors.
otherwise, the existing code would produce results that vary
by units, with potentially incorrect label sizes and spacing
between instances when generating layout devices and subcells
from a netlist.
tech files, as the first implementation was repeating one too many
times. Also: The wrong type was being read for the number of steps,
although the resulting value was correct.
(1) Dimension properties were not output correctly.
(2) Magic insisted that the output file was <cell>.tcl, not <file>.tcl,
although the error was only in the messaging
(3) Magic was incorrectly renaming the cell to <cell>.tcl after writing
the file.
units; although that is a more proper usage, it also happens to
break a lot of existing scripts. Since virtually all of these
scripts start out with "snap internal" to force units, I have kept
this single usage, when "units" is still set to "default". That
keeps the older scripts from breaking, while hopefully scripts get
updated over time to use "units" instead of "snap". Note that there
are still ways to make this behavior break, such as running
"units microns" to set units and then sourcing a script that assumes
that "snap internal" will change the units, which will then not
happen. But batch scripts should be handled property with backwards-
compatibility mode.
".tcl" off of the name, so that the cell name remains the same, and
(2) it uses "units" instead of "snap", as the latter is no longer
used for setting the unit type.
differentiating between bar and square contacts on input. Also:
added handling of the "mask-hints" operator for GDS input as
well as GDS output. This is a bit more realistic now that the
mask hint properties are handled as scalable integers and not as
character strings.
grid rescaling while reading a GDS AREF record. The previous
commit is still valid and prevents excessive warnings and
unnecessary rescaling when a bogus value is given for an array
pitch when the array has only one row or one column. But the
scaling was still incorrect and would potentially cause an
error if an array pitch was at a finer scale than any data read
before it, forcing a valid grid rescaling. This now works
correctly.
to force internal units to be used; this usage is now deprecated
and needed to be changed to the "units" command. Also: Fixed a
separate issue with getting both "view bbox" and "view get" to
return values in the currently selected units. Also: Fixed an
issue with "property" when setting a property to a list passed as
a single value (e.g., "property FIXED_BBOX [box values]"), which
needed to null the string after each value.
magic to complain about reading GDS_START and GDS_END properties
from a .mag file, although its fallback method handles the properties
correctly, anyway, so there is no actual impact other than the
error message.
R. Timothy Edwards