This variable can be set to a string, which will be included in the
argument list when capacitance extraction is initiated through the
interface, with the Run Extraction button in the Run page
of the Cap Extraction panel, or through the !fc command.
The variable tracks the FcArgs text entry area in the Run
page of the Cap Extraction panel, from where the variable is
most conveniently set or edited.
If the interface detects that FasterCap from FastFieldSolvers.com is being used, and this entry is empty, the
default argument string
will be imposed. A ``-b'' option will always be added if
missing from the FasterCap arguments list, as this argument is
necessary for correct FasterFap operation in this mode. The
``-a'' option is almost always used, as it specifies
auto-refinement, however it is technically not necessary and won't be
imposed if not given, except in the case where no arguments are given
If this variable is set, then the Run Extraction button in the
Cap Extraction panel Run page will initiate a process
running in the foreground. If not set, jobs are run in the
background, so that the user can continue using Xic while the run
is in progress.
It is not clear why there would be any reason to run in the
foreground, except possibly for debugging.
This variable controls, and is controlled by, the setting of the Run in foreground check box in the Run page of the Cap
Extraction panel from the Extract Menu.
The capacitance extraction interface uses a special layer for masking
of objects to be included in the capacitance extraction run. By
default, this layer is named ``FCAP''. If any shapes exist on
this layer in the current cell hierarchy, all objects will be clipped
by these shapes before capacitance extraction. If no shapes are found
on this layer, then all objects in the current cell hierarchy will be
included in capacitance extraction.
If this variable is set to the name of an existing layer name in the
layer table, that layer will do the clipping.
If this variable is set, then the standard output from the running
capacitance extraction program is printed in the console, in addition
to being saved in a file. The console is the shell window from which
Xic was started. This allows the user to monitor the run, and
abort if something isn't correct.
This will also apply if the program is being run in the foreground,
however operation is a bit different. In this case, a ``| tee''
is added to the command string ahead of the output file name. There
are two implications: the text will be block buffered, and therefor
won't appear in the window immediately, and in Windows, there is no
native tee command so that the operation may fail. However, a
tee command is provided with the Cygwin tools, and there are
other sources. In the normal case of running in the background,
output will again be block buffered under Windows, but there is no
requirement for a tee command.
This variable mirrors the state of the Out to console check box
in the Run page of the Cap Extraction panel from the Extract Menu.
Value: real number 1e3 - 1e6.
When not using a capacitance extraction program that provides
automatic refinement, such as FasterCap from FastFieldSolvers.com, this provides a crude panel refinement
capability. This variable provides a number, and the interface will
attempt to split all panels into equal area pieces, where the total
number of pieces is the number given. The refined panels are output
into the list file, which consequently can grow large.
When not set, no such refinement is done. It should not be set for
normal use of FasterCap, but is needed if using the Whiteley
Research version of FastCap or similar.
Value: directory path string.
This variable can be set to a full path to the capacitance extraction
If this is not set, Xic will attempt to use ``/usr/local/bin/fastcap'' as the FastCap program (or ``/usr/local/bin/fastcap.exe'' in Windows). If this executable does
not exist, Xic will attempt to find ``fastcap'' (or ``fastcap.exe'' in Windows) in the shell search path when running in
the foreground, and background runs will fail.
This tracks the setting of the text entry field in the Run
page of the Cap Extraction panel.
Value: real number 0.0 - 100.0.
If set to a positive value, the substrate is modeled to extend
horizontally outward by this value beyond the bounding box of the
extracted geometry. See the discussion in the interface description
in 16.17.1 for more information. If not set, no dimensional
change is assumed.
Value: units string.
This variable can be used to specify the length units used in
generated capacitance extraction input files. The variable can be set
to a string consisting of one or the abbreviations ``m''
(meters), ``cm'' (centimeters), ``mm'' (millimeters),
``um''" (microns), ``in'' (inches), and ``mils''.
The long form word will also be accepted. This variable is most
conveniently manipulated with the choice menu found in the Cap
Extraction panel Params page.