cxy(4)							     Kernel Interfaces Manual							    cxy(4)

Name
       cxy - CXY08 communications interface

Syntax
       device dhu0 at uba0 csr 0160440 flags 0x?? vector dhurint dhuxint

Description
       A  CXY08 provides eight communication lines with modem control adequate for UNIX dialup use. The device behaves and looks just like a DHV11
       and is specified in the configuration line the same as a DHV11 device.  Each line attached to the CXY08 communications interface behaves as
       described in and can be set to run at any of 16 speeds. See for the encoding.

       Bit  i of flags can be specified for a device to say that a line is not properly connected and that the line should be treated as hardwired
       with carrier always present.  Thus, specifying flags 0x04 in the specification of would cause line tty02 to be treated in this way.

       The driver normally interrupts on each input character.	The and devices operate under the control of the driver.

Diagnostics
       dhu%d: receive fifo overflow
       The character input fifo overflowed before it could be serviced.  This can happen if a hard error occurs when the CPU is running with  ele-
       vated  priority,  as the system then prints a message on the console with interrupts disabled.  This can cause a few input characters to be
       lost to users.  It is not serious.

       dhu%d:%d DMA ERROR
       A DMA transfer error has occurred.  The unit number and line number are printed.  This means that  the  channel	indicated  has	failed	to
       transfer  DMA data within 10.7 microseconds of the bus request being acknowledged or that there is a memory parity error.  This may cause a
       few output characters to be lost.

       dhu%d: DIAG. FAILURE
       This indicates that the internal diagnostics have detected an error.

       dhu%d: DHU HARDWARE ERROR.  TX.DMA.START failed
       The failed to clear the start bit.  Normally, this is cleared to signal that a DMA transfer has completed.

Files
       Dialups

See Also
       tty(4), MAKEDEV(8)

																	    cxy(4)