> I don’t know much of CPU IP licensing, but I would think one pays more for the design of the CPU than for the ISA.
You have a couple of options:
- Use a ready made CPU design (eg. Cortex-M) and pay license $$ for each chip sold.
- Use an existing ISA (eg. ARMv4), build your own CPU around it and pay license $ for each chip sold.
- Use RISC-V, build your own CPU around it and pocket those $ you'd otherwise pay for the ISA license (or reduce your price to become more competitive, or something inbetween)
(And then there #4: Design your own ISA.
Now you also have to deal with standard software: compilers, kernels, some libraries. Still may make sense in some cases, but why go through the trouble if all you want is to save some pennies per chip on the ISA?)
In all but the first case, your CPU design is a one-time cost that becomes marginal over the (hopefully many) chips you sell. Especially microcontrollers can be _very_ high volume where this makes sense (more so with the IoT hype that's going on).
Which is why I think it's a wise idea for them to aim for that market first and build up experience and a war chest.
You have a couple of options: - Use a ready made CPU design (eg. Cortex-M) and pay license $$ for each chip sold. - Use an existing ISA (eg. ARMv4), build your own CPU around it and pay license $ for each chip sold. - Use RISC-V, build your own CPU around it and pocket those $ you'd otherwise pay for the ISA license (or reduce your price to become more competitive, or something inbetween)
(And then there #4: Design your own ISA. Now you also have to deal with standard software: compilers, kernels, some libraries. Still may make sense in some cases, but why go through the trouble if all you want is to save some pennies per chip on the ISA?)
In all but the first case, your CPU design is a one-time cost that becomes marginal over the (hopefully many) chips you sell. Especially microcontrollers can be _very_ high volume where this makes sense (more so with the IoT hype that's going on).
Which is why I think it's a wise idea for them to aim for that market first and build up experience and a war chest.