[binarycoffee]

Not only is the instruction set simple, but the clock-per-instruction cost is deterministic, so assembly code is ideal for real-time I/O. Just like GP, we found that we could often use a PRU in place of an FPGA and dramatically cut development cost (this was for very small production series).

One use case for C is communication with the CPU (remoteproc stuff). We commonly had one PRU handle CPU communication with trivial C code while another PRU on the same PRU subsystem was coded with assembly to handle real-time I/O.