Minimal Setup for sky130 - Enviroment

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This tutorial requires sudo access. If you are not the owner of the server or system, you should use a virtual machine or Docker.

Notation Guides:

• $ means Ubuntu shell commands
• % means tcl/tk console
• ln[1] means interactive Python command
• UPPERCASE words denote user-defined paths

Install MAGIC

1. Install dependent packages

   CentOS uses yum instead of apt-get for package management. Package names could be slightly different.

   $ sudo apt-get install m4
   $ sudo apt-get install tcsh
   $ sudo apt-get install csh
   $ sudo apt-get install libx11-dev
   $ sudo apt-get install TCL-dev tk-dev
   $ sudo apt-get install libcairo2-dev
   

2. Clone Magic source

   Make or go to a directory for the source DIR_FOR_SOURCE and clone the source from Git.

   $ cd DIR_FOR_SOURCE
   $ git clone git://opencircuitdesign.com/magic
   

   If it doesn’t work, clone the GitHub mirror.

   $ git clone https://github.com/RTimothyEdwards/magic
   

   The command apt-get install magic installs an outdated version!

3. Compile and Install

   This step requires sudo access.

   $ cd magic
   $ ./configure
   $ make
   $ sudo make install
   

4. Test

   You can run Magic in any directory.

   $ magic &
   

   Check Magic’s cell search path with the following:

   % path
   

   If CAD_ROOT appears after “System search path is”, you need to set CAD_ROOT as an environment variable pointing to where Magic’s basic libraries are installed. The default is ‘/usr/local/lib’.

Install XSCHEM, NETGEN, NGSPICE

1. XSCHEM

   Install the following packages using sudo apt-get install

   

   Clone the XSCHEM source and install:

   $ cd DIR_FOR_SOURCE
   $ git clone https://github.com/StefanSchippers/xschem.git_
   $ cd xschem
   $ ./configure --prefix=ROOT_FOR_XSCHEM (default: '/usr/local')
   $ make
   $ make install
   

2. NETGEN

   $ cd DIR_FOR_SOURCE
   $ git clone git://opencircuitdesign.com/netgen
   $ cd netgen
   $ ./configure
   $ make
   $ sudo make install
   

3. NGSPICE

   NGSPICE uses wget instead of git clone.

   $ cd DIR_FOR_SOURCE
   $ wget https://sourceforge.net/projects/ngspice/files/ng-spice-rework/37/ngspice-37.tar.gz
   $ tar -zxvf ngspice-37.tar.gz
   $ cd ngspice-37
   $ mkdir release
   $ cd release
   $ ../configure --with-x --enable-xspice --enable-cider --enable-openmp --with-readlines=yes --disable-debug
   $ make
   $ sudo make install
   

Install SKY130-PDK

1. Google/Skywater open SKY130-PDK

   Clone the PDK source from GitHub and activate submodules. Since laygo2 doesn’t use digital standard libraries, we install primitive and IO libraries only.

   $ cd DIR_FOR_SOURCE
   $ git clone https://github.com/google/skywater-pdk
   $ cd skywater-pdk
   $ git submodule init libraries/sky130_fd_io/latest
   $ git submodule init libraries/sky130_fd_pr/latest
   $ git submodule update
   $ make timing
   

2. Set up PDK using open-pdks

   The open-pdks app installs Skywater-PDK into the PDK_ROOT directory and generates Magic library files with them. It also downloads some useful third-party libraries, such as primitives for XSCHEM.

   $ cd DIR_FOR_SOURCE
   $ git clone git://opencircuitdesign.com/open_pdks
   $ cd open_pdks
   $ ./configure --enable-sky130-pdk-DIR_FOR_SOURCE/skywater-pdk --disable-alpha-sky130
   

   Before installing, consider these configuration options:

   1. --prefix=PDK_ROOT
      • PDK files are installed in ‘PDK_ROOT/share/pdk’
      • Default PDK_ROOT: ‘/usr/local’
      • We use the default path in this tutorial
   2. --enable-xschem-sky130[=PATH]
      • If not disabled, the third-party Sky130 setup for XSCHEM will be installed as part of the sky130A PDK.
      • If the path is omitted or the configuration option is not specified, the library will be pulled automatically from the repository and installed.
      • To disable the package, use --disable-xschem-sky130.
   3. --enable-alpha-sky130[=PATH]
      • The third-party alphanumeric layout library will be installed. Everything else is identical to option 2.

   After choosing and setting the configuration, you can install. It could take some time.

   $ make
   $ sudo make install
   

Set Startup Files for MAGIC and XSCHEM

1. MAGIC

   Create a symbolic link mapping sky130 tech-files into the MAGIC system search path.

   $ sudo ln -s SKY130A_INTALL_ROOT_DIR/sky130A/libs.tech/magic/* /usr/local/lib/magic/sys/
   

   The default SKY130A_INTALL_ROOT_DIR is ‘/usr/local/share/pdk’, which is identical to “PDK_ROOT/share/pdk”.

   Set the .magicrc file in your home directory.

   $ cd ~
   $ cat > .magicrc 
   source $CAD_ROOT/magic/sys/sky130A.magicrc
   

   Test whether it’s connected well.

   $ magic &
   % path
   

   It’s successful if the result looks like the image below.

   

2. XSCHEM

   Check xschem_sky130 library

   The xschem_sky130 library should have been installed in SKY130A_INSTALL_ROOT_DIR/sky130A/libs.tech.

   $ cd SKY130A_INSTALL_ROOT_DIR/sky130A/libs.tech
   $ cd xschem
   $ ls
   

   If the following directories don’t appear, you should download them manually.

   

   Set xschemrc

   $ cd ~/.xschem
   $ cat > xschemrc
   source /usr/local/share/pdk/sky130A/libs.tech/xschem/xschemrc (press ctrl+D to finish writing)
   $ xschem
   

   The result should look like the image below. Select the desired cell and press ‘e’ to check various circuits.