PWM1A and PWM1B of Beaglebone Black no response

I gotta a problem about the PWM1A and PWM1B of my BBB.

I have edit “/boot/uEnv.txt” to enable the device tree overlay and deploy the “BB-PWM1-00A0.dbto


I edit the value of “/sys/class/pwm/pwm-1.8/period”, “/sys/class/pwm/pwm-1.*/duty_cycle” and “/sys/class/pwm/pwm-1.*/enable” to “100 000 000” , “50 000 000” and “1” respectively and checked them to ensure the values are written to them successfully.


I expect that there should be waveform output with period = 100 ms and duty cycle cycle 50 ms on both of the PWM1A and PWM1B which are corresponding to P9_14 and P9_16. But I found that there are no such expected output.


My BBB Image version is “Debian Buster IoT Image 2020-04-06


May I ask if anybody can help to point out what’s going wrong in my steps above?