Running NETEX-I on Linux or Solaris


This page describes the basic procedure for running NETEX using the GUI: NETEX-I for NETEX Interactive).

NETEX-I enables the user to select the GDSII file, select (or create/edit) the technology file (containing the stackup information) and to select/create the configuration file which controls the NETEX engine's behavior.

For this tutorial, we start by making the examples directory the current one and then load the file called demo.gds. To do that cd to the examples directory and type:

$ ..bin/netexi [enter]

Loading the GDSII File

From the main menu, click on the Browse button to select the GDSII file to process. Select demo.gds from the examples directory.

Selecting the Structure

The top level structure name will is displayed by default. You can change that if you want to process a different cell/structure. In this example we will accept the cell called TOP.

Selecting the Technology File

Click on the Browse button (next to the title, Technology File Name) to select the Technology file to use. For this example, pick the file: tlib.lib. The technology file editor allows you to define the layer stackup. For this example the stackup is pre-defined, but when loading a a new GDSII file for the first time you should create a "new" technology file and define the stackup. Once created, the technology file can be used again. Details on the contents and syntax of the technology file can be found here

  Loading and Configuring NETEX

Click on the Browse to select the configuration file. Pick bycoord.cfg which demonstrates how one extracts nets by specifying the a coordinate point on each net of interest.

Clicking on the Extractions tab to see/edit the output file name that will be generated containing the extracted nets. Click on the Edit button next to it to see/edit the specified coordinates/layer/label.

Contents of the configuration file are explained in detail here.

  Output Menu

NETEX can produce several different output formats depending on your target software. For our example, select the GDSII output. We will then view the output with our Qckvu GDSII viewer. Optional output formats are described in detail here.

  Running the Net Extraction

Click on the Compute Nets button to start the extraction process. After a few seconds (this demo is very small) it will complete and write the output file to disk.

Click on the View Output button to view the GDSII file just produced -- bycoords.gds (this assumes you have installed Qckvu and configured it as the GDSII viewer)

Note: NETEX first creates a GDSII file called demo_neall.gds which contains all the nets in the input file - it then uses the extraction specification to produce a smaller GDSII file that contains only the extracted nets. Both files contain the same entity data (polygons/layers) as the input file, but the output files are organized by nets and the original hierarchy is gone.

  Using Qckvu to view individual nets

Once in Qckvu, you may click on the structure navigator dialog to review the extracted. Elements of each net are collected into their own cell. You can select the top level cell to see all nets or view each net separately by selecting its name and hitting the Apply button.

417 Ingalls St. Unit C, Santa Cruz, CA 95060 831.426.6163 email: