dmb(4)
NAME
dmb − DMB32 communications multiplexor
SYNTAX
device dmb0 at vaxbi? node? flags 0x????
vector dmbsint dmbaint dmblint
DESCRIPTION
A DMB32 device provides eight communication lines with modem control. The device driver also supports a connection to a line printer through the line printer port of the DMB32.
Each line attached to a DMB32 serial line port behaves as described in tty(4). Input and output for each line may independently be set to run at any of 16 speeds; see tty(4) for the encoding.
Bit i of flags may be specified for a dmb to say that a line is not properly connected, and that the line should be treated as hard-wired with carrier always present. Thus, specifying “flags 0x0004” in the specification of dmb0 would cause line 2 on the DMB32 to be treated as hard-wired with carrier always present.
RESTRICTIONS
The DMB32 provides a synchronous port, but this is not supported by the driver.
DIAGNOSTICS
dmbinit: device broken
This message is produced at system boot time if the DMB32 fails its internal self test.
dmb%d: fifo overflow
The character input fifo overflowed before it could be serviced. This can happen if the cpu is running with elevated priority for too long a period of time. No user interaction is required.
dmb%d: DMA Error. tbuf = 0x%x
A DMA output transfer failed. This could be caused by a memory error or an invalid pte. For a description of the error code in the "tbuf" register, see the DMB32 User Guide.
dmb%d: Modem Error. tbuf = 0x%x
Indicates a problem with a modem or its cable. For a description of the error code in the "tbuf" register, see the DMB32 User Guide.
dmb%d: Internal Error. tbuf = 0x%x
Indicates that the DMB32 detected an internal error. For a description of the error code in the "tbuf" register, see the DMB32 User Guide.
dmb%d: uio move error
An error occurred when copying a printer buffer from user space to system space.
dmbsint
The unsupported synchronous port of the DMB32 interrupted because of a problem. Check your interrupt vectors for a conflict with another device.
FILES
/dev/tty??
/dev/ttyd?(modem lines only)