NAME
ucom —
USB tty support
SYNOPSIS
To compile this driver into the kernel, place the following line in your kernel configuration file:
device ucomAlternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
ucom_load="YES"
DESCRIPTION
Theucom 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.
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 devices
- /dev/cuaU*
- for callout ports
- /dev/cuaU*.init
- /dev/cuaU*.lock
- corresponding callout initial-state and lock-state devices
SEE ALSO
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)
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 device names created today. Old scripts must be
adjusted accordingly.