NAME    [Toc]    [Back]

     addcom - multiplexing serial communications interface

SYNOPSIS    [Toc]    [Back]

     addcom0 at isa? port 0x108 irq 5
     com* at addcom? slave ?
     or
     pccom* at addcom? slave ?

DESCRIPTION    [Toc]    [Back]

     The addcom driver provides support for Addonics FlexPort 8/S
(and probably
 FlexPort 4/S) boards that multiplex together up to eight
(or four)
     EIA RS-232C (CCITT V.28) communications interfaces.

     Each addcom device is the master device for up to eight  com
devices.  The
     kernel  configuration  specifies  these com devices as slave
devices of the
     addcom device, as shown in SYNOPSIS.  The slave ID given for
each com device
 determines which bit in the interrupt multiplexing register is tested
 to find interrupts for that device.  The port  specification for the
     addcom  device is used to compute the base addresses for the
com subdevices.
  The port for the interrupt multiplexing register  is
fixed, so it
     is  doubtful  that more than one addcom can be used in a machine.

FILES    [Toc]    [Back]

     /dev/tty??

SEE ALSO    [Toc]    [Back]

     com(4), intro(4), isa(4)

HISTORY    [Toc]    [Back]

     OpenBSD support for addcom devices first appeared in OpenBSD
3.0.

OpenBSD      3.6                           July      16,     2001