Using a PWM channel to get square waves (don't care about duty cycle) from my BeagleBone, looks like I can get up to 50MHz with:
root@beaglebone:~# echo 10 > /sys/devices/ocp.3/pwm_test_P9_14.12/period
root@beaglebone:~# echo 5 > /sys/devices/ocp.3/pwm_test_P9_14.12/duty
root@beaglebone:~# echo 10 > /sys/devices/ocp.3/pwm_test_P9_14.12/period
root@beaglebone:~# echo 5 > /sys/devices/ocp.3/pwm_test_P9_14.12/duty
