Creating a New Project

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Before doing this, you need to do the Technology_Setup.

Creating a project directory

You will need to create a separate directory where you will create your libraries:

mkdir LayoutTutorial
cd LayoutTutorial

For FreePDK45

In this directory, you need to setup some of the library files using either the bash script:

/projects/cmpe122/techfiles/FreePDK45/ncsu_basekit/cdssetup/ ( /mada/software/techfiles/FreePDK45/ncsu_basekit/cdssetup/ for VLSI-DA lab)

This will copy several files into the current directory if they do not exist. It should only need to be run the first time.


The first thing you must do is copy the system wide technology library to your project (or home) directory:

cp /mada/software/techfiles/NCSU_CDK_1.5.1/.cdsinit .cdsinit

Running Virtuoso

From this directory, run virtuoso:

virtuoso &

Note that the ampersand runs the command in the background so you can do other things in the shell. Do not close the shell or the program will also close.


After you start virtuoso, the first window that pops up is the command interface window (CIW). It looks like this:


Library Manager

Another window may pop up which is the Library Manager. If it doesn't show automatically, you can view it with Tools->Library Manager. The important libraries that will show up in the manager are:

  • NCSU_DeviceLib_FreePDK - contains transistor models
  • NCSU_TechLib_FreePDK - contains Pcells (parameterized cells) for transistors and vias
  • basic - contains power supplies

For SCMOS, similar directories will be:

  • NCSU_TechLib_tsmc02d - the design rules and via layouts
  • NCSU_Analog_Parts - the transistor models
  • basic - contains power supplies
2-library manager.jpg

Creating a Library

The first step is to create a new library with File->New->Library. Add a unique name for your library. It will contain all of your layout and schematics. We will also "attach" the library to a given technology library that is already set up.

3-new library.jpg

Selecting the technology

Screenshot-Technology File for New Library.png
5-attach to technology lib.jpg

For FreePDK45

A special window will pop up that prompts you to pick a technology library. We are going to use the NCSU_TechLib_FreePDK45 technology which is a "fake" 45nm process. It cannot actually be manufactured.


We are going to use the NCSU_TechLib_tsmc02d technology which is a SCMOS 180nm process. It can be manufactured by several different vendors including TSMC.