3 ms·
Are PRUs their version of the RP 2040's Programmable IO (PIO)?
by jgalt212 3y ago
Are PRUs their version of the RP 2040's Programmable IO (PIO)?
- nvy 3y agoPRU stands for Programmable Real-time Unit. The soc on the original Black had two 200MHz PRUs which ran independently of the main processor and could be used for signalling and sensing tasks that require tight timing guarantees, and can then trigger interrupts on the main CPU.
- jgalt212 3y agoso yes, then.
- m00x 3y agoIt's kind of a middle ground, it looks more like a barebones MCU. RP2040's PIO is extremely limited with only 9 available instructions, this looks a bit more involved, but functionally it's very similar.
- crest 3y agoThe PRUs are simple single-issue in-order CPUs designed to make cycle-counting easy. They are more than an accidentally turing complete useful combination of a down-counter and shift-register. Don't get me wrong the RP2040 PIO is a very flexible, powerful peripheral for a sub-$1 MCU. A single PRU is probably larger than the whole RP2040.
- MisterTea 3y agoThe 2040's PIO is indeed similar but the PRU has features the PIO doesn't like IOs directly wired to CPU register bits so the result of an instruction is immediately available on IO lines. edit: also Ti's PRU has been around waaaay longer than the RP2040 so the PRU is likely an inspiration for the PIO.