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.Dd July 16, 2005
.Dt EN 4
.Os
.Sh NAME
.Nm en
.Nd "device driver for Midway-based ATM interfaces"
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device en"
.Cd "device atm"
.Cd "device utopia"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
if_en_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
device driver supports Midway-based ATM interfaces including the
Efficient Networks, Inc.\& ENI-155 and Adaptec ANA-59x0.
Midway is an AAL5 SAR (Segmentation and Reassembly) chip.
.Pp
For configuring the card for IP see
.Xr natmip 4 .
.Pp
The following sysctls are recognized by the driver additionally to those
handled by
.Xr utopia 4 :
.Bl -tag -width indent
.It Va hw.atm.enX.istats
Contains an array of
.Vt uint32_t
with internal driver statistics.
.It Va hw.atm.enX.debug
This is a bit map of debugging options.
This variable is only available when the driver is compiled with debugging
support.
.El
.Pp
The driver supports the media options
.Cm sdh ,
.Cm noscramb
and
.Cm unassigned
(see
.Xr utopia 4 ) .
.Sh DIAGNOSTICS
.Bd -literal
en0 <Efficient Networks ENI-155p> rev 0 int a irq 5 on pci0:16
en0: ATM midway v0, board IDs 6.0, Utopia (pipelined), 512KB on-board RAM
en0: maximum DMA burst length = 64 bytes
en0: 7 32KB receive buffers, 8 32KB transmit buffers allocated
.Ed
.Sh CAVEATS
The driver extensively uses DMA on PCI.
The first
generation PCI chipsets do not work or exhibit poor performance.
.Sh SEE ALSO
.Xr natm 4 ,
.Xr natmip 4 ,
.Xr utopia 4 ,
.Xr ifconfig 8 ,
.Xr route 8
.Sh AUTHORS
.An Chuck Cranor
of Washington University implemented
.Nm
driver in 1996 for
.Nx .