Hi, I am wondering how a company that uses a publicly available CPU core from your website in an FPGA or maybe ASIC design is protected from infringing patents or other rights of the companies that originally developed the CPU architecture and instruction set? I am aware of e.g. the MIPS versus Lexra case and the patented instructions for unaligned load & store, and I have noticed how your simple MIPS I core has special notes (disclaimers) about not implementing these specific instructions. But does that make the core legal to use professionally? Similarly, do you risk being sued for using e.g. one of your 8051, Z80, PIC or AVR microcontroller cores, for which I am not aware that there are any (non-expired) patents associated? Assuming there are no direct patent infringements, could there still be copyright or license issues that effectively prevent you from using such a CPU core without getting a permission from the "owner" of the instruction set - even if we assume the CPU core have been developed completely from scratch (ie. based only on a public description of the instruction set/opcodes)? I have tried to look around opencores.org for general comments on this subject, but with no luck so far. I believe it must be a question of general interest to anybody considering using public/open IP that implements "industry standard" CPU instruction sets or similar cores that could be subject to copyright or license issues. Thanks, Claus -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.opencores.org/forums.cgi/cores/attachments/20070112/5f74faa8/attachment.htm

On 1/11/07, Claus Høyer choyer at computer.org> wrote: The short answer: No warranty expressed or implied. Any risk of patent infringement is borne by the company actually implementing the design. I haven't done any research into the history of instruction sets, but it's belief that they're not covered by copyright. Most instruction sets are such a muddled mess of instructions stolen from other machines and architectures that it would be difficult to prove ownership in any case. The architecture defense I know of has been done mostly through patents, with occasional trademark claims (as I recall, MIPS has sued in the past for companies claiming their processors were "MIPS-compatible"). Personally, for the Z80 core, security is based mainly on the fact that any architecture patents will have expired by now. Also, in the time most 8-bit CPUs were made, efficient silicon implementation of those instructions was what was valued (and protected); most patents on these would not apply to a synthesizable core. IANAL, YMMV. - Guy -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.opencores.org/forums.cgi/cores/attachments/20070112/ebac5dfa/attachment.htm

Copyright does not cover making something work based on it's public description, and so, in general is moot for this, unless copyrighted HDL was used and not built from scratch or only public domain HDL sources. The leaves patents, which it's best to ask a lawyer... That said, most of the CPUs on here are over 20 years old (patent life), and so I wouldn't expect it to be much of an issue, but really is something you want to ask a lawyer (or whatever company that made the original IP) and not this list.... ________________________________ From: cores-bounces at opencores.org [mailto:cores-bounces at opencores.org] On Behalf Of Claus Høyer Sent: Thursday, January 11, 2007 5:10 PM To: cores at opencores.org Subject: [oc] CPU core patent, copyright or license issues Hi, I am wondering how a company that uses a publicly available CPU core from your website in an FPGA or maybe ASIC design is protected from infringing patents or other rights of the companies that originally developed the CPU architecture and instruction set? I am aware of e.g. the MIPS versus Lexra case and the patented instructions for unaligned load & store, and I have noticed how your simple MIPS I core has special notes (disclaimers) about not implementing these specific instructions. But does that make the core legal to use professionally? Similarly, do you risk being sued for using e.g. one of your 8051, Z80, PIC or AVR microcontroller cores, for which I am not aware that there are any (non-expired) patents associated? Assuming there are no direct patent infringements, could there still be copyright or license issues that effectively prevent you from using such a CPU core without getting a permission from the "owner" of the instruction set - even if we assume the CPU core have been developed completely from scratch (ie. based only on a public description of the instruction set/opcodes)? I have tried to look around opencores.org for general comments on this subject, but with no luck so far. I believe it must be a question of general interest to anybody considering using public/open IP that implements "industry standard" CPU instruction sets or similar cores that could be subject to copyright or license issues. Thanks, Claus -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.opencores.org/forums.cgi/cores/attachments/20070112/8105f320/attachment.htm

Claus Høyer wrote:


FWIW, the unaligned load-store patent should have expired Dec 23, 2006.

-hpa

H. Peter Anvin ha scritto:
Yeah, and we had a party that day!!! BTW, is Transmeta going to develop its own clone?... :) Does anyone know if there are other patents covering specific instructions of other ISAs, such as MIPS32, MIPS64 or PowerPC? Cheers, Fabrizio -- ============================================ Fabrizio Fazzino - fabrizio at fazzino.it Fazzino.IT - http://www.fazzino.it ============================================