HDL designs are conceptually like software source code: They're a human-readable format for expressing functionality, which is mechanically converted into a format which more directly implements that function. If the design is being used with reconfigurable hardware (e.g. an FPGA), the synthesized bitfile is loaded an run much like ordinary software in a stored-program computer. While they might embody some technique protected by patent law, the designs themselves are protected by copyright.
There are enough differences, though, that I'm not sure how well the common existing free software licenses (or other software licenses) map to HDL designs. Words like "compile," "link," "library," "object code," and "header file" don't translate exactly. In general, HDL designs can be used to make either reconfigurable logic device bitfiles or permanently-fixed hardware. When the end product is an ASIC, the software thought model (and licenses) may not apply as well.
The goal of this project is to identify clarifications or improvements which would be helpful for licensing Free Software in HDL forms.
If you are interested, please look at the following:
- OpenCores forum discussion of LGPL
- OpenCores essay "Open Source for Hardware"
- TAPR Open Hardware License (OHL)
- Technocrat forum discussion of OHL, grep for RTL and HDL
- Article "Toward Open Source Hardware"
The above seems like a good solution to me. If you don't like it, contact me and suggest something better!
Now, go to the Wiki!