diff options
-rw-r--r-- | share/man/man4/nmdm.4 | 35 |
1 files changed, 20 insertions, 15 deletions
diff --git a/share/man/man4/nmdm.4 b/share/man/man4/nmdm.4 index 1fcc17b..f811d6e 100644 --- a/share/man/man4/nmdm.4 +++ b/share/man/man4/nmdm.4 @@ -32,23 +32,21 @@ .Sh DESCRIPTION The .Nm -driver provides support for a device-pair termed a -.Em null modem pair . -A null modem pair is a pair of character devices. -Each device provides to a process an interface identical -to that described in -.Xr tty 4 . -However, whereas most other devices which provide the -interface described in +driver provides two .Xr tty 4 -have a hardware device of some sort behind them, the +devices connected +by a virtual "null modem" cable. +.Pp +If either of the two tty devices have the CDSR_OFLOW bit +("stty dsrflow") +set in their line discipline, the .Nm -device has, instead, another process manipulating -it through the other half of the pair. -That is, anything written on the first device is -given to the second device as input and anything written -on the second device is presented as input on the first -device. +device will emulate the speed configured in the +.Xr termios 4 +settings. +The speed emulation works independently in the two directions, +controlled by the slower ends termios settings (c_ispeed, c_ospeed, +CS5...CS8, CSTOPB and PARENB). .Sh FILES .Bl -tag -width /dev/nmdm[N][AB] -compact .It Pa /dev/nmdm Ns Ar N Ns Op Pa AB @@ -59,9 +57,16 @@ node has a matching .Pa B node. .El +.Pp +The +.Nm +driver implements "on-demand device creation" so simply accessing a +given instance in /dev will create it. .Sh DIAGNOSTICS None. .Sh SEE ALSO +.Xr stty 1 , +.Xr termios 4 , .Xr tty 4 .Sh HISTORY The |