dmc(4) [bsd man page]
DMC(4) Kernel Interfaces Manual DMC(4) NAME
dmc - DEC DMC-11/DMR-11 point-to-point communications device SYNOPSIS
/sys/conf/SYSTEM: NDMC dmc_controllers # DMC11 DESCRIPTION
The dmc interface provides access to a point-to-point communications device which runs at either 1 Mb/s or 56 Kb/s. DMC-11's communicate using the DEC DDCMP link layer protocol. The dmc interface driver also supports a DEC DMR-11 providing point-to-point communication running at data rates from 2.4 Kb/s to 1 Mb/s. DMR-11's are a more recent design and thus are preferred over DMC-11's. The NXMT and NRCV constants in the driver should be increased in this case, as the DMR can accept up to 64 transmit and receive buffers, as opposed to 7 for the DMC. The configuration flags specify how to set up the device, 0 -- full duplex DDCMP (normal mode) 1 -- DDCMP Maintence mode (generally useless) 2 -- DDCMP Half Duplex, primary station 3 -- DDCMP Half Duplex, secondary station Several device error counters are available via "adb", for more information see the adb script /usr/share/adb/dmcstats, or the DMC11 tech- nical manual. The host's address must be specified with an SIOCSIFADDR ioctl, and the destination address specified with a SIOCSIFDSTADDR ioctl, before the interface will transmit or receive any packets. ROUTING
The driver places a HOST entry in the kernel routing tables for the address given in the SIOCSIFDSTADDR ioctl. To use the DMC as a link between local nets, the route to the remote net must be added manually with the route(8) command, or by the use of the routing process routed(8) on each end of the link. DIAGNOSTICS
dmc%d: bad control %o. A bad parameter was passed to the dmcload routine. dmc%d: unknown address type %d. An input packet was received which contained a type of address unknown to the driver. DMC fatal error 0%o. A fatal error in DDMCP occurred, causing the device to be restarted. DMC soft error 0%o. A non-fatal error in DDMCP has occurred. dmc%d: af%d not supported. The interface was handed a message which has addresses formatted in an unsuitable address family. SEE ALSO
intro(4N), inet(4F) BUGS
The current version of the driver uses a link-level encapsulation so that multiple protocol types may be used. It is thus incompatible with earlier drivers, including the 4.2BSD version. 3rd Berkeley Distribution October 22, 1996 DMC(4)
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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)