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PWM(8)			    System Manager's Manual			PWM(8)

NAME
       pwm -- configure	PWM (Pulse Width Modulation) hardware

SYNOPSIS
       pwm [-f device] -C
       pwm [-f device] [-D | -E] [-I] [-p period] [-d duty]

DESCRIPTION
       The  pwm	 utility  can  be  used	to configure pwm hardware.  pwm	uses a
       pwmc(4) device to communicate with the  hardware.   Some	 PWM  hardware
       supports	 multiple  output  channels  within a single controller	block;
       each pwmc(4) instance controls a	single PWM channel.

       pwmc(4) devices are named /dev/pwm/pwmcX.Y, where X is  the  controller
       unit number and Y is the	channel	number within that unit.

       The options are as follows:

       -f device  Device to operate on.	 If not	specified, /dev/pwm/pwmc0.0 is
		  used.	 If an unqualified name	is provided, /dev/pwm is auto-
		  matically prepended.

       -C	  Show the configuration of the	PWM channel.

       -D	  Disable the PWM channel.

       -d duty	  Configure  the  duty cycle (in nanoseconds or	percentage) of
		  the PWM channel.  Duty is the	portion	of the	period	during
		  which	the signal is asserted.

       -E	  Enable the PWM channel.

       -p period  Configure the	period (in nanoseconds)	of the PWM channel.

       -I	  Invert PWM signal polarity

EXAMPLES
          Show	the configuration of the PWM channel:

	   pwm -f /dev/pwm/pwmc0.1 -C

          Configure  a	 50000	ns period and a	25000 ns duty cycle and	enable
	   the channel:

	   pwm -f pwmc1.1 -E -p	50000 -d 25000

          Configure a 50% duty	cycle on the device  and  channel  which  were
	   configured in pwmc(4) to have the label backlight:

	   pwm -f backlight -d 50%

SEE ALSO
       pwm(9), pwmbus(9)

HISTORY
       The pwm utility appeared	in FreeBSD 13.0.

AUTHORS
       The  pwm	 utility  and  this manual page	were written by	Emmanuel Vadot
       <manu@FreeBSD.org>.

FreeBSD	13.2			 June 17, 2019				PWM(8)

NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | SEE ALSO | HISTORY | AUTHORS

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