Creating Netlists

Front End Flow is able to produce netlists in non-ADS formats. These netlists can then be used within various non-ADS design tools. For more information, refer to the Netlist Exporter Setup documentation.

Creating a Netlist

To create a Front End Flow netlist, use the following procedure:

Open the design to be netlisted (refer to the ADS Schematic Capture and Layout documentation for information on opening designs).
Note
The design must be saved with a title at least once prior to netlisting. Front End Flow netlisting options will not be activated for untitled designs.
From the Schematic window, select the menu option Tools > Netlist Export > Create ADS Front End netlist . The Create ADS Front End Netlists dialog appears (see Create Front End Flow Netlists Dialog).
Select the desired design tool from the Tool drop-down list. Front End Flow will produce a netlist compatible with that tool.

Note
The tool will be remembered between ADS sessions, so it will not be necessary to select the tool every time a netlist is generated. The Tool drop-down list is constructed each time the dialog window is brought up, and will give you choices that are available based on the component definition directories that are within the component path. In this example, the tools Assura, Calibre, and Dracula are available.

Create Front End Flow Netlists Dialog

The Design to Netlist field contains the design name that will be netlisted (source file). The field defaults to the design name that is in the active window. If you prefer, enter a different design to netlist.
Click the Netlist file Browse button, or directly enter the full path and file name, to define the file that will be created by the netlister (target file).
Note
If no path is specified, the file will be created in the currently opened project's directory.

Caution
If the specified Netlist file already exists, it will be overwritten without warning.
Click the Log file Browse button, or directly enter the full path and file name, to define the log file name. The Log file will contain any netlisting errors or warnings.
Note
If no path is specified, the file will be created in the currently opened project's directory.

Caution
If the specified Log file already exists, it will be overwritten without warning.
Click the Modify Include File List checkbox to specify the files to include in the final netlist. For more information, refer to Including Files in Netlists.
Click the Modify Option List checkbox to specify the options that will be output into the header of the netlist file. For more information, refer to Setting up Options for a Netlist.

Specify comments within the Comments section that you would like to have output into the header of the netlist.

Select the Include date and time as a comment to place a comment line in the file that specifies the date and the time that the netlist was generated.
Select the Include design name as a comment to place a comment line in the file that specifies the design used to generate the netlist.

Enter comment text, to be included in the header of the netlist file, within the edit text box (located below the Include design name as a comment checkbox).

Note
Comments from the edit box will be automatically output with the line comment character, so it is not necessary to type the comment character with the comments. The comments will be remembered through the current ADS session only. They are not stored between ADS sessions.

Click the View netlist file when finished checkbox to load the netlist file into the standard text editor after netlisting is finished. This allows you to visually inspect it for netlisting errors. An example netlist file is shown in Example Netlister Netlist File.

Example Netlister Netlist File

Click the View log file when finished checkbox to load the netlist file into the standard text editor after netlisting is finished. An example log file is shown in Example Netlister Log File.

If neither the View netlist file when finished nor the View log file when finished checkbox is set, an information dialog will appear that informs you that netlisting has completed.

Example Netlister Log File

Click OK to create the netlist.

Including Files in Netlists

Most IC Foundries place symbols within schematics that refer to subcircuits. These subcircuits will typically contain parasitic and non-parasitic devices. Subcircuit component representation allows for a more accurate representation than primitive device representation. Since a single foundry process may use multiple design tools with different subcircuit definitions, most foundries elect to include model files in the final netlist. The Front End Flow netlister allows the inclusion of model files within netlists, although this is not a preferred practice for the ADS simulator.

Caution
Options defined in include files will be set regardless of the settings in the Options dialog (see Setting up Options for a Netlist).

Defining Files to Include

To define the files to include in a netlist, use the following procedure:

If not already open, open the Create ADS Front End Netlists dialog (from the Schematic window, select the menu option Tools > Netlist Export > Create ADS Front End netlist ).
Select the desired design tool from the Tool drop-down list.
Click the Modify Include File List button. The Include Files dialog will appear (see The Include Files Dialog).

The Include Files Dialog
Add or cut automatically included files as required. See Automatically Included Files for information about these files.
Add or cut user specified include files as required. See User Specified Include Files for information about these files.
Click OK to close the Include Files dialog.
Refer to Creating a Netlist to create the netlist.

Automatically Included Files

To determine the files listed in Automatically Included Files , Front End Flow will check all paths, looking for an include subdirectory under any netlist_exp directory that contains components (the component definitions should always be in an netlist_exp directory). If the include directory contains a directory for the tool selected in the Create ADS Front End Netlists dialog, all of the files within the tool directory will be included in the Automatically Included Files list. For example, all of the files located within the directory $HOME/hpeesof/netlist_exp/include/dracula will be included in the list if $HOME/hpeesof/netlist_exp contains components and dracula is the selected tool. These files can be manually removed from the list, see Cutting Automatically Included Files.

Note
If new files are added into the directories that have automatically included files, they will show up in the Automatically Included Files list the next time the Create ADS Front End Netlists dialog is opened.

Normally, the automatically included files will be a part of a design kit, and will contain specific subcircuits necessary for simulation or LVS. These files can also be placed in other directories if there are particular options that must be set for all newly created designs. In the example, the two files, standard.inc and indBox.inc , were placed in $HOME/hpeesof/netlist_exp/include/dracula , see User Specified Include Files. The two files will be included automatically in every project.

Viewing Automatically Included Files

Files within the Automatically Included Files list can be viewed by selecting the file to view and clicking the view button. This will open the file in the ADS text editor.

Cutting Automatically Included Files

All files that are under the include directories will be in the Automatically Included Files list until manually removed, see Automatically Included Files.

To remove files from the list, use the following procedure:

If not already open, open the Create ADS Front End Netlists dialog (from the Schematic window, select the menu option Tools > Netlist Export > Create ADS Front End netlist ).
Select the desired design tool from the Tool drop-down list.
Click the Modify Include File List button. The Include Files dialog will appear.
Select the file within the Automatically Included Files field to cut.
Click the cut button under the Automatically Included Files field.
Repeat steps 3 and 4 as required. Click OK .
This will remove the selected files from the Automatically Included Files list. The removed files will remain removed from session to session. Files can be added back into the Automatically Included Files list by using the add procedure.

Adding Automatically Included Files

To add files back into the list (that were previously cut), use the following procedure:

If not already open, open the Create ADS Front End Netlists dialog (from the Schematic window, select the menu option Tools > Netlist Export > Create ADS Front End netlist ).
Select the desired design tool from the Tool drop-down list.
Click the Modify Include File List button. The Include Files dialog will appear.
Click the add button under the Automatically Included Files field. The Add Automatically Included Files dialog appears (see Add Automatically Included Files Dialog).

Add Automatically Included Files Dialog

Select the file to include.
Click OK or Apply to add the file.
Repeat steps 5 and 6 as required.
If there are no files left to include, and you press the Apply dialog, the dialog will automatically be dismissed.

User Specified Include Files

Files that are not in an include directory can be selected for inclusion into the netlist by adding these files in the User Specified Include Files list. These files can reside in any path. User specified include files are useful for selecting files that need to be included for a one time usage or files that are under test.

Adding User Specified Include Files

To add files into the list, use the following procedure:

If not already open, open the Create ADS Front End Netlists dialog (from the Schematic window, select the menu option Tools > Netlist Export > Create ADS Front End netlist ).
Select the desired design tool from the Tool drop-down list.
Click the Modify Include File List button. The Include Files dialog will appear.
Click the add button under the User Specified Included Files field. The ADS file browser appears.
Select the file to include.

Click OK in the browser.

Note
Make sure to select the correct file; Front End Flow does not validate the format of the included file. The list of files to include will be stored in a configuration file, so the user specified include file list is maintained between ADS sessions.

Cutting User Specified Include Files

To remove files from the list, use the following procedure:

If not already open, open the Create ADS Front End Netlists dialog (from the Schematic window, select the menu option Tools > Netlist Export > Create ADS Front End netlist ).
Select the desired design tool from the Tool drop-down list.
Click the Modify Include File List button. The Include Files dialog will appear.
Select the file within the User Specified Included Files field to cut.
Click the cut button under the User Specified Included Files field.
Repeat steps 3 and 4 as required. Click OK .

Example Include File

For this example the Include Files dialog shown in The Include Files Dialog will be used. Clicking the view button with the standard.inc file selected in the Include Files dialog, will open the file in the text editor, as shown in The standard.inc file.

The standard.inc file in this example automatically sets the appropriate Dracula options for LVS. The file contains three lines, and will set the .BIPOLAR, .CAPVAL, and .RESVAL options.

The standard.inc file

Since standard.inc files has options set within it, you may not want it to be included in the final netlist. That is, the appropriate options are already set by using the options dialog and you do not want the standard.inc options to override them. In this case, cut the standard.inc file from the Automatically Included File list, see Cutting Automatically Included Files.

Setting up

Setting up Options for a Netlist

This section refers to options for a particular tool that are output into a netlist (for example, .Temp=25 in a SPICE netlist). Front End Flow has an options dialog that can be configured for each tool. For information on how to configure the options dialog, refer to the Netlist Exporter Setup documentation.

Note
Options defined in include files will be set regardless of the settings in the Options dialog (see Including Files in Netlists).

Setting Netlist Options

To set or modify netlist options, use the following procedure:

If not already open, open the Create ADS Front End Netlists dialog (from the Schematic window, select the menu option Tools > Netlist Export > Create ADS Front End netlist ).
Select the desired design tool from the Tool drop-down list.
Click the Modify Option List button.
A dialog that is specific to the selected tool will be displayed. For information on each option for a specific tool, you must consult the documentation for that tool.
Select the options you want contained in your netlist.
Click OK to close the options dialog.
The selected options will be saved in the file, < tool >.cfg, in the current project's directory. The options are available for later use.
Note
The option format in the netlist will be dependent on the tool being used.
Refer to Creating a Netlist to create the netlist.

Setting Netlist Options Example

In this example, the selected tool is Dracula. When the Modify Option List button is clicked, the Dracula Options dialog appears (see Dracula Option Dialog).

Dracula Option Dialog

The Dracula Options dialog has been configured to contain only the Dracula netlist options relevant to ADS. In addition, the Dracula Options dialog is set up to have dependent options become enabled or disabled based on whether certain options are set. For example, if .BIPOLAR is set as an option, the options within the Bipolar Options group box will all become enabled.

Each tool's options dialog may have different behavior depending on the approach taken when customizing for your use. For more information, refer to the Netlist Exporter Setup documentation.

When the OK button is clicked, the selected options will be saved in the file, < tool >.cfg, in the current project's directory. The options are available for later use.

The option format in the netlist will be dependent on the tool being used. For Dracula, each option outputs with the line comment character (therefore, for a simulator, the Dracula options would be seen as comments).