PIO is supposedly patent pending. Other CPUs have similar ideas, but none in the hobby space that I'm aware of. For example, Infineon Tricore has PCP (Peripher

PIO is supposedly patent pending. Other CPUs have similar ideas, but none in the hobby space that I'm aware of. For example, Infineon Tricore has PCP (Peripheral Control Processor), which is more advanced but serves an identical role - offloading time-critical pin manipulation interrupt service from the CPU to a dedicated IO coprocessor.