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UCOM(4)			 BSD Kernel Interfaces Manual		       UCOM(4)

NAME
     ucom -- USB tty support

SYNOPSIS
     To	compile	this driver into the kernel, place the following line in your
     kernel configuration file:

	   device ucom

     Alternatively, to load the	driver as a module at boot time, place the
     following line in loader.conf(5):

	   ucom_load="YES"

DESCRIPTION
     The ucom driver attaches to USB modems, serial ports, and other devices
     that need to look like a tty.  The	ucom driver shows a behavior like a
     tty(4).  This means that normal programs such as tip(1) or	ppp(8) can be
     used to access the	device.

SYSCTL VARIABLES
     The following variables are available as both sysctl(8) variables and
     loader(8) tunables:

     hw.usb.ucom.debug
	     Debug output level, where 0 is debugging disabled and larger val-
	     ues increase debug	message	verbosity.  Default is 0.

     hw.usb.ucom.device_mode_console
	     When set to 1, the	ucom driver will mark terminals	as console de-
	     vices when	operating in device mode.  Default is 1.

     hw.usb.ucom.pps_mode
	     Enables and configure PPS capture mode as described below.

Pulse Per Second (PPS) Timing Interface
     The ucom driver can capture PPS timing information	as defined in RFC
     2783.  The	API, accessed via ioctl(2), is available on the	tty device.
     To	use the	PPS capture feature with ntpd(8), symlink the tty device to
     /dev/pps0.

     The hw.usb.ucom.pps_mode sysctl configures	the PPS	capture	mode.  It can
     be	set in loader.conf(5) or sysctl.conf(5).  The following	capture	modes
     are available:
	 0     Capture disabled	(default).
	 1     Capture pulses on the CTS line.
	 2     Capture pulses on the DCD line.

FILES
     /dev/ttyU*	      for callin ports
     /dev/ttyU*.init
     /dev/ttyU*.lock  corresponding callin initial-state and lock-state	de-
		      vices

     /dev/cuaU*	      for callout ports
     /dev/cuaU*.init
     /dev/cuaU*.lock  corresponding callout initial-state and lock-state de-
		      vices

SEE ALSO
     cu(1), tty(4), uark(4), ubsa(4), ubser(4),	uchcom(4), ucycom(4),
     ufoma(4), uftdi(4), uhso(4), uipaq(4), umcs(4), umct(4), umodem(4),
     umoscom(4), uplcom(4), usb(4), uslcom(4), uvisor(4), uvscom(4), ttys(5)

HISTORY
     The ucom driver was adopted from NetBSD in	March of 2002.	This manual
     page was adopted from NetBSD by Tom Rhodes	<trhodes@FreeBSD.org> in April
     2002.

BUGS
     Prior to FreeBSD 6.0 ucom created /dev/ucom? rather than the uniform de-
     vice names	created	today.	Old scripts must be adjusted accordingly.

BSD				 July 11, 2020				   BSD

NAME | SYNOPSIS | DESCRIPTION | SYSCTL VARIABLES | Pulse Per Second (PPS) Timing Interface | FILES | SEE ALSO | HISTORY | BUGS

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