Time sync PRU with ARM

I am trying to time sync a couple of beaglebone black PRUs to each other.

I have ptp running on my boards and so I have time synced my Linux user spaces but cannot figure out a way to time sync the user space with the PRU.

I want to do this so i can turn the “real time” hardware constraints that PRU supplies into actually real time.

Trying to control the Fast I/O pins in synchrony.

Any thoughts or suggestions?


probably the simplest thing would be to provide a hardware signal to a GPIO pin that all PRUs are busy-looping on; this should provide a 5ns resolution.