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## ext2sim, exttosim

Convert extracted file(s) to a ".sim" format file.

### Usage:

> ext2sim [option]

> > where option is one of the following:
> > [run] [runtime_options]
> >   Run exttosim on current cell, with command-line options (see Summary, below).
> > alias on|off
> >   Enable/disable alias (.al) file. This file contains all of the node aliases (different node names that correspond to the same node). If "off", the statements are output directly to the .sim file. If "on", the statements are moved to the ".al" file.
> > labels on|off
> >   Enable/disable labels (.nodes) file. The labels file is used by the extresist command.
> > default
> >   Reset to default values
> > format MIT|SU|LBL
> >   Set output format
> > rthresh [value]
> >   Set resistance threshold value. Lumped resistances below this value will not be written to the output. The value is in ohms, or may be the keyword infinite to prohibit writing any lumped resistances to the output.
> > cthresh [value]
> >   Set capacitance threshold value. The value is in femtofarads, or may be the keyword infinite to prohibit writing any parasitic capacitances to the output.
> > merge [merge_option]
> >   Merge parallel devices/transistors. The valid merge options are:

> >   > conservative
> >   >   Merge transistors and capacitors having the same device type and node connections and having the same width and length. Widths are summed in the final output for transistors. Capacitor values are summed in the final output.
> >   > aggressive
> >   >   Merge transistors having the same node connections and having the same length. Widths are summed in the final output. Merge any capacitors having the same device type and node connections. Capacitance is summed in the final output.
> >   > none
> >   >   Do not merge any devices.

> > extresist on|off
> >   Incorporate output from the command extresist into the final `.sim` file.
> > help
> >   Print help information

### Summary:

> Without options, or with the option run, the ext2sim command converts the hierarchical extracted netlist information produced by the extract command in a series of `.ext` files into a flattened representation in the `.sim` format, used for switch-level simulation.

> runtime_options may be passed on the command line, and represent the original command-line options passed to the standalone version of ext2sim. A number of the original command-line options have been deprecated in the Tcl-based version, and some are duplicated by other ext2sim options. Valid runtime_options are:

> > -B
> >   Don't output transistor or node attributes in the .sim file. This option will also disable the output of information such as the area and perimeter of source and drain diffusion and the FET substrate.
> > -F
> >   Don't output nodes that aren't connected to devices (floating nodes).
> > -t char
> >   Trim characters from node names when writing the output file. char should be either "#" or "!". The option may be used twice if both characters require trimming.
> > -y num
> >   Select the precision for outputting capacitors. The default is 1 which means that the capacitors will be printed to a precision of 0.1 fF.
> > -J hier|flat
> >   Select the source/drain area and perimeter extraction algorithm. If hier is selected then the areas and perimeters are extracted only within each subcell. For each device in a subcell the area and perimeter of its source and drain within this subcell are output. If two or more devices share a source/drain node then the total area and perimeter will be output in only one of them and the other will have 0. If flat is selected the same rules apply, only the scope of search for area and perimeter is the whole netlist. In general, flat (which is the default) will give accurate results (it will take into account shared sources/drains).

> With options, the command sets various parameters affecting the output format and content.

### Implementation Notes:

> ext2sim is implemented as a separate loadable Tcl package, but one which depends on the presence of the standard "tclmagic" package. magic is set up with a placeholder command for ext2sim, and will automatically load the Tcl package when this command is invoked.

> exttosim is an alias for ext2sim, to satisfy the grammatically anal retentive. ext2sim is also implemented as a script to be run from the shell command line, where it executes magic in batch mode (i.e., using the -dnull option) and runs the ext2sim command automatically. With this usage, the syntax is:

> > ext2sim [ magic_options -- ] ext2sim_runtime_options ext_file

> The double-dash separates command options passed to magic on startup (such as "-T technology" to specify the technology) from those runtime options (see above) passed to the ext2sim command.

### See Also:

> extract
> extresist
> ext2spice
> irsim

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Last updated: September 13, 2021 at 12:31pm