More recently, people have experimented with repurposing the ARISC power management core on Allwinner H3-based boards like the Orange Pi for similar realtime pu

More recently, people have experimented with repurposing the ARISC power management core on Allwinner H3-based boards like the Orange Pi for similar realtime purposes: https://github.com/orange-cnc/h3_arisc_firmware https://github.com/orange-cnc/h3_arisc_firmware (It's basically an outdated OpenRISC core with direct access to some GPIO pins running at up to a few hundred megahertz.)