NAME

scc, duart, uart − serial communication control

SYNOPSIS

­bind -a #t /dev
 ­/dev/eia0
­/dev/eia0ctl
­/dev/eia1
­/dev/eia1ctl

DESCRIPTION

The serial line devices serve a one-level directory, giving access to the serial ports.  There are several devices serving the same files; the particular one used depends on the machine involved.  ­Eia0 is a stream data file.  It can be read and written to use that port.  Reads will block until at least one character is available.  ­Eia0ctl is a stream control file associated with the port.  ­Eia1 and ­eia1ctl are similar, but for a second serial line. 

The ­ctl file can be used to push stream modules onto the port.  One can also write one of the following textual commands to a ­ctl file:

bn Set the baud rate to n.

dn Set DTR if ­n is non-zero; else clear it. 

kn Send a break lasting ­n milliseconds. 

rn Set RTS if ­n is non-zero; else clear it. 

mn Obey modem CTS signal if ­n is non-zero; else clear it. 

pc Set parity to odd if ­c is o, to even if ­c is e; else set no parity. 

sn Set number of stop bits to n. Legal values are 1 or 2.

ln Set number of bits per byte to n. Legal values are 5, 6, 7, or 8.

SOURCE

­/sys/src/9/port/devscc.c
­/sys/src/9/∗/devduart.c
­/sys/src/9/∗/devuart.c

Plan 9  —  April 04, 1995