Here are some resources you could use to get started.

https://www.embeddedrelated.com/showarticle/586.php http://elinux.org/ECE497_BeagleBone_PRU http://processors.wiki.ti.com/index.php/PRU_Linux_Applicatio... http://hackaday.com/2014/06/22/an-introduction-to-the-beagle...