What pins do SET PWM[] output to in PRU speak?


I’ve watched through the two “Hands-On BeagleBone Black Tutorial” videos and I’ve gotten the DIO working with PRU speak, but I can’t figure out where the pin “SET PWM[0], 50” is outputting to. The “DIO[0], 1” works just fine but “PWM[0], 50” doesn’t do anything. I’m using the image provided in http://beagleboard.org/pru.

Also what is the max amount of PWM ports I can use when using the PRU on the BeagleBone Black?