ARM cancelled their architecture license and sued them, Qualcomm won, but with a threat like that to your core business it's best to have an escape hatch.

They'll need to license future versions of the ARM ISA and now they know the licensor is hostile.

They are basically acquiring talent and/or preexisting IP. RISC-V is free but implementations are the sole IP of the company.

Implementing ARM and RISC-V decoders might depend on licensing fine print for each licensee

Eating the competitor is one way to win. If you're scared of them, just buy them out.

> They don't need to license RISC-V.

Correct. However you need circuitry on silicon to implement said architecture which is the expensive and time consuming part.

There are a lot of little cores in phones doing little core things. Having a first rate design team experienced in an ISA that is royalty free probably makes sense. They'll be able to expand the use of RISCV up the value chain ver time.

Buying a team that's already working on RISCV also reduces the chances of ARM lawyers getting involved.

https://patents.justia.com/assignee/ventana-micro-systems-in...

RISC-V being freely available does not mean that implementations of it will not be patented from here to the Orion nebula and back.

> Actually, I wonder if it would be possible to design a chip with both an ARM and a RISC-V decoder on the same die and just fuse-off the ARM die on select units to avoid any fees...

That's not quite what Raspberry Pi did with the RP2350 (the ARM and RV cores are wholly separate) but they did include the ability to fuse off one side or the other, so I wonder if they'll release a cheaper RV-only version at some point.

It's probably just for IP and talent acquisition, if I had to guess. People who can design high performance server-class CPU microarchitectures are rare.

Frankly, Ventana seemed like an interesting entry in the space, but I have no idea who would have actually bought their servers at the end of the day. They taped out multiple designs, but none actually seem to exist outside their labs. I don't really see any path to meaningful RISC-V server adoption for at least several more years and by that time Qualcomm could design something on their own, assuming they are serious about re-entering the market. Grabbing the talent and any useful IP/core design components makes the most sense to me, anyway.

QC likely use a lot of Arm IP, Nuvia notwithstanding, and want a way out of the general Arm monopoly. Seems to be a growing trend.

A dual ISA decoder with with fuse-off options will likely have unwelcome power-perf-area and yield consequences.

Acquihire and hedging bets.