User talk:Notarm

ARM vs. SuperH
Hi, regarding your first and only edit. I did go looking if you're entirely right.

I didn't confirm at ARM that they bought patents from Hitachi. I still find it likely. I did find a section in their docs from 2012 comparing "A device based around the SH-4A processor core supports the SH-4A version of the SuperH architecture. The SuperH architecture was developed by Hitachi in the early 1990s, beginning with the SH-1. The SH-2, SH-2A, SH-3, SH-4 and SH-4A have continued the evolution of the architecture with various extensions and performance improvements. After brief ownership by SuperH Inc (a joint venture between Hitachi and ST Microelectronics), the SuperH product line is now developed by Renesas Technology."

I also see here: An interesting article on the new RZ series and the collaboration with ARM Limited: https://www.renesas.com/en-eu/about/web-magazine/edge/solution/15-rz.html comp.arch (talk) 23:55, 15 December 2018 (UTC)
 * Hi, thanks for your feedback. I'm not sure what it is about the Thumb instruction set you think likely was dervived from the Hitachi SH. Architectures with instruction widths that do not match the ALU width predate Thumb and SH by 30 years, which is why I mentioned the Cray-1 as a notable example, and that's about all they have in common. The aspect of ARM processors such as ARM7TDMI that made it so successful is that Thumb is in addition to the full ARM instruction set, so that the user can choose what code needs to be fast (and compiled to/written in ARM code run from 32 bit memory), and what code could be slower (and compiled to/written in Thumb code and run from 8/16 bit memory), therefore there was no compromise, it was the best of both worlds, and no other architecture could do both. The relevant US patent is 5740461. Secondly, ARM didn't license any patents from anyone at all during this timeframe, that actually doesn't make sense for a company building it's own IP portfolio.Notarm (talk) 05:08, 16 December 2018 (UTC)