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.Dd July 17, 2010
.Dt DZ 4 emips
.Os
.Sh NAME
.Nm dz
.Nd
.Tn eMIPS
console serial device interface
.Sh SYNOPSIS
.Cd "dz* at ebus0 addr ?"
.Sh DESCRIPTION
This serial line provides a simple communication line with no modem control.
It is not adequate for
.Ux
dialup use.
.Pp
Normal I/O
control parameters for individual lines are managed by
.Xr ioctl 2
calls.
Line speeds may be initiated via
the
.Xr ttys 5
file,
.Xr stty 1
or
.Xr ifconfig 8
to name a few,
see
.Xr tty 4 .
.Pp
The
.Nm dz
driver monitors the rate of input on each board,
and switches between the use of character-at-a-time interrupts
and input silos.
While the silo is enabled during periods of high-speed input,
the driver polls for input 30 times per second.
.Sh FILES
.Bl -tag -width /dev/tty[0-9][0-9]xx -compact
.It Pa /dev/ttyD0
phys interface.
.El
.Sh DIAGNOSTICS
.Bl -diag
.It dz%d: silo overflow .
The 1 character input silo overflowed before it could be serviced.
This can happen if a hard error occurs when the
.Tn CPU
is running with elevated priority, as the system will
then print a message on the console with interrupts disabled.
It is not serious.
.El
.Sh SEE ALSO
.Xr stty 1 ,
.Xr tty 4 ,
.Xr ttys 5 ,
.Xr getty 8
.Sh HISTORY
A
.Nm
driver appeared in
.Nx 6.0 .