In this HDL repository, there are many different and unique modules, consisting of various HDL (Verilog or VHDL) components. The individual modules are developed independently, and may be accompanied by separate and unique license terms (such as GPL, LGPL, BSD, modified BSD, commercial or others). Your license rights with respect to individual modules accompanied by separate license terms are defined by those terms. The license agreement for each module is generally located in the module source code. Nothing else shall restrict, limit, or otherwise affect any rights or obligations you may have, or conditions to which you may be subject, under such license terms. This agreement does not limit your rights under, or grant you rights that supersede, the license terms of any particular module. The mere aggregation of these modules (putting them side by side in the same source code repository or on a hard disk) does not mean that there is one master license for all the files. It is up to you, the user, to ensure that during the building a project, which combines these modules together so that they form a bit file (either one, or multiple for partial reconfiguration), all the individual licenses are compatible. For example, if a single module is covered by the GPL, the whole combination must also be released under the GPL—if you can't, or won't, do that, you may not distribute the resulting bit file. The majority of ADI created modules are dual-licensed, allowing the user to pick which license they want to use, (and the any rights and obligations they have). - The ADI BSD license. (which allows you to makeg bit files, and not release your source, as long as it attaches to an ADI device) o This is not truly open source, since it does place extra restrictions on developers. - The GPL v2 license (which allows you to make bit files, but you must release all other HDL (except vendor produced, which we consider a run-time library, permitted by GPL section 3), along with your bitfile). o This is truly open source, and places no additional restrictions on use or fields of endeavor. The GPL is ideal for use cases such as open source projects with open source distribution, student/academic purposes, hobby projects, internal research projects without external distribution, or other projects where all GPL obligations can be met. In these cases, support is handled via web (https://ez.analog.com/community/fpga), on a best effort basis. If you do not feel we are answering your questions fast enough on engineerzone - remember that our best efforts may not match your product development schedule. Free, non-deterministic support is not a replacement for professional services (contractors). If you need something done in a specific time frame - hire a professional. Just as you are free to use HDL modules you find here (under that module's license), you are free use an alternative, which may include commercial/deterministic support. Specific modules which do not follow this (this list may not be complete, it's up to each user to check each module license): - SPDIF : which is released under the LGPL license only. + Please go to https://opencores.org/project, spdif_interface for support - The ADI created JESD Core, which is released under the GPL and a commercial license only. + The commercial license gives you the full rights to create and distribute bit files on your own terms without any open source license obligations, and special avenues for support may be possible.