Did you check the System Reference Manual?
http://circuitco.com/support/index.php?title=BeagleBone#Rev_A6
As to sleep, as has been mentioned before, there is no sleep support currently available in the kernel. That is under development at the moment.
As to the PRU, there is no PRU currently available in the Kernel we release, so no measurements have been taken with a PRU running and would depend on exactly what the PRU was running.
Gerald