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NAME

     ar - synchronous Digi/Arnet device driver

SYNOPSIS

     device ar

     device sppp

DESCRIPTION

     The ar driver supports the Digi/Arnet SYNC/570i ISA and PCI cards that is
     based on the HD64570 chip.  Both the 2 and 4 port cards are supported and
     auto detected.

     The standard FreeBSD sppp code is used for the link level layer.  The
     default protocol used is PPP.  The Cisco HDLC protocol can be used by
     adding link2 to ifconfig(8).

     Alternately, the driver can be compiled to support netgraph(4) (see
     below).

NUMBERING

     Only one line for each card is needed in the kernel configuration file.
     The first card’s ports will be installed from ar0.  The numbering of the
     next card will continue where the first stopped, e.g. if the first card
     is a two port card it will use ar0 and ar1.  The next card will then
     start at ar2.

     The card only supports IRQ 3, 5, 7, 10, 11, 12 and 15.

     The iomem area is a 16Kb block and must start at a 16Kb boundary.

NETGRAPH SUPPORT

     If the kernel is compiled with options NETGRAPH then the sppp and Cisco
     HDLC modes are disabled (and the sppp driver is unneeded), and this
     driver functions as a netgraph(4) node with a single hook named rawdata.
     Connecting to this hook enables the transmission of raw HDLC frames.  The
     node will have the same name as the device with ‘‘sync_’’ prepended,
     e.g., sync_ar0.

DIAGNOSTICS

     ar%d: Warning illegal interrupt %d.  The card cannot use the specified
     interrupt.  Choose a different one.

SEE ALSO

     cx(4), netgraph(4), netintro(4), sr(4), ifconfig(8)

HISTORY

     The ar device driver first appeared in FreeBSD 2.2.

AUTHORS

     The ar device driver was written by John Hay 〈jhay@FreeBSD.org〉.
     Netgraph support was added by Julian Elischer 〈julian@FreeBSD.org〉.

BUGS

     At the moment only the V.35 and X.21 interfaces are tested.  The others
     may need tweaks to the clock selection code.

     The code can probably stand some optimizing.

     Please report bugs to 〈jhay@FreeBSD.org〉.