ARM ate everybody's lunch, it seems.
- x86 and x64 are too power-hungry for small systems.
- Power is still up and running, but also on the high end, too (see Power 8 and 9).
- MIPS32 cores are found in lower-end MCUs. AFIACT MIPS actively offers their cores for embedding in MCUs, like ARM.
- You can still buy MCUs with Atmel AVR and 8051 8-bit architectures on the lowest end.
What's lost? SPARC and Motorola 680x0, I presume. I frankly wonder what prevented 680x0 from getting into widespread MCUs. Apparently Phillips used it their custom controllers for some time.
People should just select modern ones, and not the same old 16F84/877 or something legacy like that, that's been obsolete for like 25 years already. All of the modern ones have very uniform programming interface, nicely configurable I/O and a lot of analog features.
Not anymore that I'm aware of. They laid off most (possibly all?) of their architectural engineers around 2020 and sold off the remaining rights to a Chinese firm.
There's still a few MIPS-based MCUs out there, like PIC32, but they're a dying breed. ARM Cortex-M is much better suited to these applications.
> I frankly wonder what prevented 680x0 from getting into widespread MCUs.
Poor IPC, high interrupt latency. The weird mixed 16/32-bit nature of the 68000 made it easier to implement a microcomputer with (since you only needed 16-bit RAM/ROM), but would only get in the way in a microcontroller (where memory would mostly, if not entirely, be internal). It's a shame; I liked the ISA, but the performance just isn't there.
I almost did a prank post when Apple came out with/announced the M1. I had recently had tore down my broken PSVR which has the very nicely stamped ARM M1 in it. I wanted to post something like "Apple didn't invent it, Sony did!" Regretfully, I did not.
I don't think that's correct. The Cortex-M1 is an soft-core-only design; there's no hardware implementation. (And moreover, the ARM cores used aren't usually part of the external markings on a chip.)
What chip were you looking at? I don't see anything which looks like that in the iFixit teardown: https://www.ifixit.com/Teardown/PlayStation+VR+Teardown/6934...
It was a gen1 model, so it didn't look anything like those photos on that teardown.
Or perhaps I am not a target audience of this hardware change.
AVR is still reasonably easy to understand and manually bit-twiddle, but virtually all ARM cores are way too complicated for that. It is essentially required to use a SDK to handle all the gory details for you.
If you want to get a proper idea of what a modern ARM microcontroller architecture is like, I recommend you take a look at the RP2040 datasheet: https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.p...