The Dump Elec Netlist Button: Dump Electrical Netlist

The Dump Elec Netlist button in the Extract Menu creates a netlist file from the electrical connectivity information in the current cell. Upon pressing this button, a small pop-up appears, which provides a number of format options. The options include the names from the EnetFormat blocks in the format library file, if any. The format library provides a mechanism for user-specified formatting of netlist output. The supplied xic_format_lib file provides a formatter for Cadence DEF (Design Exchange Format), and a simple example format.

There are two built-in format choices: net and spice. Any combination of the formats can be selected, and the output will contain a block for each selected format, for each cell. In addition, there is one format option, list bottom-up, which applies to all formats.

The format options will be described in more detail below. Below the format check boxes there is a Depth choice menu which allows setting of the depth into the hierarchy to process. The user is given the option of creating the netlist to an arbitrary depth in the hierarchy. If the given depth is greater than zero, the subcells above the indicated depth will also be added to the file. If ``all'' is selected, the full hierarchy will be output.

Below the depth menu is a text entry area for the name of the file to be generated. The default name is the base name of the current cell, suffixed with ``.elecnet, to be created in the current directory. The entry area is sensitive as a receiver for drag/drop.

Any combination of the format options may be selected. The states of the option check boxes track the status of the variables described below. The listing from the Dump Elec Netlist command will have a field of output for each selected format, from each cell. Pressing the Go button will produce the output file.

The format option check boxes are described below. The first option applies to all formats.

list bottom-up
When the depth is larger than zero, this check box controls the ordering of cells in the file. When selected, the deepest cells (the ``leaf cells'') are listed ahead of their parent cells, thus the current cell will be listed last. When not selected, the listing is top-down. The current cell is listed first, followed by subcells.

The next two option check boxes specify the internal formats.

net
A netlist consisting of the terminal names associated with each wire net is generated.

spice
A SPICE listing is generated.

Additional option buttons, if any, correspond to formats specified in the format library file. If selected, a text block containing the output from the format generator will be appended to the file, for each cell. The following are available from the stock distribution format library file.

DEF
This uses a formatting script in the xic_format_lib file to generate DEF output. DEF is a common portable netlisting format. See the comments in the xic_format_lib file in the startup directory for more information.

elec-example
This uses a formatting script in the xic_format_lib file to generate output in simple example format.

Each of the option buttons that correspond to an internal format or option (not the formats from the library) has a corresponding !set variable. If the variable is changed while the pop-up is visible, the pop-up will be updated. Conversely, changing the state of the option buttons will set or unset the corresponding variables. The pop-up check box will be checked if the corresponding variable is set. The names of the corresponding variables are given in the table below.

list bottom-up	EnetBottomUp
net	EnetNet
spice	EnetSpice

If the variable CheckSolitary is set with the !set command then warnings are issued if nodes are encountered with one connection only.