Thank you. I used to design microprocessors (a LONG time ago) and TIL that there are CPUs that can operate at 225°C. Wow. And even limping along at 300°C? Wow wow.
BTW, I can't stand the 8051 architecture, but that's really off topic. I guess if you need 225, you need that chip. Reminds me of the Henry Ford / Model T quote...
8051 can certainly service interrupts quickly and predictably, which is probably all you want if you are sticking a microcontroller inside a turbine engine or oil drill.
https://www.digikey.com/catalog/en/partgroup/ht83c51/40264
> Specified Over -55 to 225°C
> Typically, parts will operate up to 300°C for a year, with derated performance.
Whether 100°C is fine for a CPU is a question for the individual CPU.