dmv(4)dmv(4)Namedmv - DMV11 communications interface
Syntax
device dmv0 at uba0 csr 0167600 flags 0x???? vector dmvrint dmvxint
Description
The interface provides access to point-to-point communications that
runs at speeds from 2.4 Kb/s to 56 Kb/s. DMV11s communicate using the
DDCMP link layer protocol.
Several protocols can be multiplexed over a link simultaneously. Con‐
versely, a can be set up so that only one protocol family can use that
device. If the latter approach is taken, an SIOCSTATE ioctl must be
issued by the protocol family requesting device ownership. The fam‐
ily's address must appear in the ``if_family'' structure member, and
``if_nomuxhdr'' must be set. Before requesting ownership, be sure to
disable access to the device for all other protocol families.
The first byte of the word can be set up to indicate what mode the
device should use. If bit 0 is clear, the device operates in point-to-
point DDCMP mode; otherwise, it operates in maintenance mode. If bit 1
is clear, the device operates in full duplex mode; otherwise, it oper‐
ates in half duplex. If bit 2 is clear, the device operates in compat‐
ibility mode; otherwise, it operates using version 4.0 of the DDCMP
protocol. The number of outstanding transmit buffers can be increased
from a default of 7 to a maximum of 24 buffers by specifying a hexadec‐
imal value in the second byte of the word. For example, if is set to
0x1800, 24 transmit buffers will be allocated on a device set up to run
full duplex in compatibility mode.
Restrictions
Note that maintenance mode should only be used to diagnose data link
problems. It is not intended to be used for normal data link traffic.
If specifying maintenance mode, do not set bit 2 of the word.
Diagnostics
dmvprobe: can't start device
The could not be started at boot time.
dmvprobe: device failed diagnostics, octal failure code = %o
The failed diagnostics at boot time.
dmvinit: can't place dmv%d into internal loopback
Unable to place the into internal loopback requested by user.
dmv%d: done unalloc rbuf
The device returned a receive or transmit buffer that was not allocated
to it.
dmv%d: unknown address type %d
An input packet was received that contained a type of address uknown to
the driver.
dmv%d bad packet address 0x%x
The device returned a buffer with an unexpected buffer address.
dmv%d: unsolicited information response: ctl = %x, data = %x
The device interrupted the driver with an information response when
none was requested.
dmvd%d: bad control %o
A bad parameter was passed to the dmvload routine.
dmv%d: modem disconnect
The modem disconnected, or there was a loss of carrier while a packet
was being received.
dmv%d: buffer too small
The remote node sent a packet that was too large to fit in the allo‐
cated receive buffer.
dmv%d: receive threshold reported
The reported a receive threshold error.
dmv%d: transmit threshold reached
The reported a transmit threshold error.
dmv%d: select threshold reached
The reported a select threshold error.
dmv%d: babbling tributary reported
The reported a babbling tributary error.
dmv%d: streaming tributary reported
The reported a streaming tributary error.
dmv%d: MOP mode entered while DDCMP was running
dmv%d: MOP mode entered while device was halted
The has entered MOP mode.
dmv%d: non existent memory reported
The accessed non-existent memory.
dmv%d: device queue overflow reported
The reported a queue overflow.
dmv%d: invalid counter pointer
The is reporting the contents of a counter when no request was made to
do so.
dmv%d: can't handle af%d
The was handed a transmit message that has addresses formatted in an
unsuitable address family.
dmv%d: internal loopback enable requested
The device is being put in internal loopback at a user's request.
dmv%d: internal loopback disable requested
The device is being taken out of internal loopback at a user's request.
dmvwatch: dmv%d hung, bse10=%b, bsell = %b, bse12=%b
The device has not responded after a long period of time.
dmv(4)
