dmv(4)							     Kernel Interfaces Manual							    dmv(4)

Name
       dmv - 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.  Conversely, 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
       operates  in  half  duplex.   If bit 2 is clear, the device operates in compatibility 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
       hexadecimal  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 allocated 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)