Frequently Asked Questions about free EDA tools.

• Q: What kinds of EDA tools are available?
  A: The basic functionality required for end-to-end board design exists. In particular, the following packages may be used:
  • System-level cascade analysis: RF Cascade.
  • Schematic capture/netlist generation: gEDA/gaf.
  • Analog circuit simulation: ngspice, tclspice, Gnucap.
  • Digital circuit simulation (Verilog): Icarus Verilog.
  • Digital circuit simulation (VHDL): Alliance VHDL.
  • Digital waveform viewing: GTKWave.
  • Board Layout: PCB.
  Also, programs exist for chip design, RF design, and so on. Indeed, a wide variety of free EDA tools are currently available, and the list is always growing! Please check OpenCollector.org for more details.


• Q: Why do these tools exist? Who wrote them, and why?
  A: As is true elsewhere in the Free Software world, free EDA tools are generally created by a dedicated group of hackers, hobbiests, and professional engineers who write programs for a wide variety of reasons. Here are some reasons:
  • To fill a need. For example, gEDA was started because no board design software was then available for Linux.
  • As a loss-leader for a consulting business. For example, ASICS.ws frequently contributes cores to OpenCores as a way to win business for their advanced consulting services.
  • As a by-product of an electronic design business. Many people believe that open-source development produces better code at lower cost than alternate business models. Companies who subscribe to this model will open-source their projects under the theory that the will attract developers to work on their projects. This is the model adopted by MultiGiG Ltd, the keepers of tclspice.
  • As a personal learning vehicle.
  • Because programming is fun!
  
  
• Q: Who supports these tools? What if I have a problem?
  A: Support is often done by the person who wrote the program. You can generally e-mail the program's creator if you need support, or have a bug to report. However, keep in mind that the program's creator is usually working as a volunteer, and may be annoyed if your problem is trivial, or if you bombard him with repeated or impolite requests for assistance. Also, since the creator is probably working for the love of it and accordingly has a day-job, please be patient -- the turn-around time on bugs can be weeks or months, depending upon how busy the creator is.

  Alternatively, as the free EDA industry develops, professional consultants will become available who will provide design and support services for a fee. With paid consultants, you can as ask as many trivial, impolite questions as you want -- as long as you pay your bill! They will also provide timely service, or at least be able to promise a delivery schedule for your request. A listing of consultants is available at Free Dog's Consultant's Corner.



• Q: Are they in use in commercial settings? Can I legally use them commercially? Do I have to release my design under the GPL if I use free tools?
  A: The tools are usually released under the GPL, which explicitly allows commercial use. Several correspondants have said that various gEDA tools are being used at their place of employment (large chip companies). Smaller electronic design consultants often use a combination of free tools and commerically available tools to perform their work. The GPL does not require you to release your design if you use GPL'ed tools to create it, just like using OpenOffice doesn't require that you release all your documents into the public domain.

  The particular case of using cores available at OpenCores is thornier. Many of the cores there are usable under the terms of the BSD licence, which allows for commercial use without any restrictions. However, a few cores are available under the GPL, meaning that you must re-distribute the source if you make and distribute products based upon them. You should always check the licensing terms on cores downloaded from OpenCores before you use them.



• Q: Will my boss kill me if I use free EDA tools at work?
  A: That depends upon how clueful your boss is. He/she may commend you on finding and using robust, high-quality software tools available at low cost!


• Q: I need a tool to do X. Where do I find it?
  A: OpenCollector is the best source to find information about free/open EDA tools. You can also post a question to the Free Dog e-mail list. The Usenet group sci.electronics.cad is often a useful resource for information about tools. As a last resort, if the tool doesn't exist yet, you might be able to convince a Free Dog member to write it!


• Q: I'm looking for design examples. What should I do?
  A: It depends upon what you are looking for.