fREEDA is a multi-physics simulator that uses compact models. It can be used as an alternative Spice circuit simulator and will read a Spice netlist as well as its own (better) native netlist with many more elemenbts supported. fREEDA uses uses state variables and many new circuit concepts supporting multi physics modeling. It minimizes energy rather than minimizing current errors and so is much more robust than Spice and with high dynamic range. Many phenomena that Spice can never model can be modeled in fREEDA. Features include easy model development, high dynamic range, and support for transient, harmonic balance and multi resolution analysis. fREEDA's large signal noise analysis captures phase noise and the effects of high levbels of noise. fREEDA also supports the integration of EM models in transient analysis. There are at least 107 different models including the major transistor models, nonlinear electro-thermal models capturing long-tail thermal effects.

fREEDA implements several types of analyses. It implements a DC, Harmonic Balance, several Time marching transient and a unique wavelet analysis. It also implements several device models including common three and four terminal transistors, transmission line, Foster's canonical form and diodes - electronic, optical and tunnel types.

fREEDA(TM) can be downloaded at http://www.freeda.org

Version: 2.0

License: LGPL

• GNU Make
• GNU C compiler gcc/g++ version 4.4.x
• GNU fortran compiler gfortran 4.4.x
• GNU flex-2.5.xx and bison-2.4.x
• The bash shell version 4.1.5
• CMake 2.8.x for the Trilinos installation

For ifreeda

• Qt 4.5.0. This includes the qmake tool, and the associated toolkit library.

It is encouraged to use Qt 4.5.0 only. Newer versions of Qt have not been tested.

see Install.md

It can be found in freeda-/doc

A new element contains a ElementName.cc and ElementName.h file. To read more about how to create an element, read the fREEDA programmer's manual in the doc directory.

Once the element is created, add the element to fREEDA by doing the following:

• Create a directory structure under the fREEDA-/simulator/elements directory. For example, if you write name your model "Capacitor", you would create a Capacitor directory inside fREEDA-/simulator/elements/c.

This Capacitor directory should contain 4 sub-directories: i) src - which will contain the Capacitor.cc and Capacitor.h files you have just created ii) bitmap - which will contain a 32x32 pixel png image of the capacitor that goes into the GUI iii) doc - Documentation for your capacitor element detailing the theory of your element, its usage in a netlist, and simulation results using this element iv) history - this folder contains previous versions of your element in case you are updating your device model with new code and want to keep a copy of your previous versions.

• In fREEDA-/simulator/elements, edit a file called makefile.list. You will add two lines to makefile.list. The first line point fREEDA to the .cc file, while the second line points fREEDA to the name of the element. See the already existing entries of that and follow that format.

• Go to fREEDA-/simulator, type "make dep". Then type "make".

• Your element file will be compiled again and the fREEDA binary file will be re-built, after which you can use your new element in a netlist.

• To add this element to the fREEDA GUI (ifreeda), see the file README_ GUI.

fREEDA has evolved because of the work of many people. Below is a list of people, many of whom are still actively involved. Please email Nikhil Kriplani at nkriplaniHERE-COMES-THE-AT-SIGNncsu.edu to become a developer or if your name may have been mistakenly left out.

Michael B Steer <mbsHERE-COMES-THE-AT-SIGNncsu.edu> Carlos Christoffersen <cechristHERE-COMES-THE-AT-SIGNvision.lakeheadu.ca> Nikhil Kriplani <nmkriplaHERE-COMES-THE-AT-SIGNunity.ncsu.edu> Senthil Velu <sveluHERE-COMES-THE-AT-SIGNunity.ncsu.edu> Sonali Luniya <srluniyaHERE-COMES-THE-AT-SIGNunity.ncsu.edu> Justin Lowry <jqlowryHERE-COMES-THE-AT-SIGNncsu.edu> Houssam Kanj <houssam_kanjHERE-COMES-THE-AT-SIGNyahoo.com> Frank Hart <fphartHERE-COMES-THE-AT-SIGNunity.ncsu.edu> Aaron Walker <alwalke3HERE-COMES-THE-AT-SIGNunity.ncsu.edu> Ramya Mohan <rmohanHERE-COMES-THE-AT-SIGNunity.ncsu.edu> Shubha Vijaychand <svijaycHERE-COMES-THE-AT-SIGNhotmail.com> Satish Uppathil <satish.uppathilHERE-COMES-THE-AT-SIGNericsson.com> T. Rob Harris <trharrisHERE-COMES-THE-AT-SIGNncsu.edu> Shivam Priyadarshi <spriyadHERE-COMES-THE-AT-SIGNncsu.edu> Chris Snowden Bill Batty