.\" $FreeBSD: head/share/man/man4/en.4 208027 2010-05-13 12:07:55Z uqs $
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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 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 .
.Sh CAVEATS
The driver extensively uses DMA on PCI.
The first
generation PCI chipsets do not work or exhibit poor performance.