NAME

       pcn — AMD PCnet/PCI Fast Ethernet device driver

SYNOPSIS

       To compile this driver into the kernel, place the following lines in your kernel configuration file:

             device miibus
             device pcn

       Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

             if_pcn_load="YES"

DESCRIPTION

       The  pcn  driver  provides  support  for  PCI Ethernet adapters and embedded controllers based on the AMD
       PCnet/FAST, PCnet/FAST+, PCnet/FAST III, PCnet/PRO and PCnet/Home Ethernet controller  chips.   Supported
       NIC's include the Allied Telesyn AT-2700 family.

       The  PCnet/PCI  chips  include  a  100Mbps  Ethernet  MAC  and  support  both  a serial and MII-compliant
       transceiver interface.  They use a bus master DMA and a scatter/gather descriptor scheme.  The AMD  chips
       provide  a  mechanism  for zero-copy receive, providing good performance in server environments.  Receive
       address filtering is provided using a single perfect filter entry for the station address  and  a  64-bit
       multicast hash table.

       The pcn driver supports the following media types:

       autoselect   Enable  autoselection  of  the  media  type and options.  The user can manually override the
                    autoselected mode by adding media options to rc.conf(5).

       10baseT/UTP  Set 10Mbps operation.  The ifconfig(8) mediaopt option can also be  used  to  select  either
                    ‘full-duplex’ or ‘half-duplex’ modes.

       100baseTX    Set  100Mbps (Fast Ethernet) operation.  The ifconfig(8) mediaopt option can also be used to
                    select either ‘full-duplex’ or ‘half-duplex’ modes.

       The pcn driver supports the following media options:

       full-duplex  Force full duplex operation.

       half-duplex  Force half duplex operation.

       For more information on configuring this device, see ifconfig(8).

HARDWARE

       The pcn driver supports adapters and embedded controllers  based  on  the  AMD  PCnet/FAST,  PCnet/FAST+,
       PCnet/FAST III, PCnet/PRO and PCnet/Home Fast Ethernet chips:

       •   AMD Am79C971 PCnet-FAST
       •   AMD Am79C972 PCnet-FAST+
       •   AMD Am79C973/Am79C975 PCnet-FAST III
       •   AMD Am79C976 PCnet-PRO
       •   AMD Am79C978 PCnet-Home
       •   Allied-Telesis LA-PCI

DIAGNOSTICS

       pcn%d: couldn't map ports/memory  A fatal initialization error has occurred.

       pcn%d: couldn't map interrupt  A fatal initialization error has occurred.

       pcn%d: watchdog timeout  The device has stopped responding to the network, or there is a problem with the
       network connection (e.g. a cable fault).

       pcn%d: no memory for rx list  The driver failed to allocate an mbuf for the receiver ring.

       pcn%d:  no  memory  for  tx  list    The  driver failed to allocate an mbuf for the transmitter ring when
       allocating a pad buffer or collapsing an mbuf chain into a cluster.

       pcn%d: chip is in D3 power state -- setting to D0  This message applies only to  adapters  which  support
       power  management.  Some operating systems place the controller in low power mode when shutting down, and
       some PCI BIOSes fail to bring the chip out of this state before configuring it.  The controller loses all
       of its PCI configuration in the D3 state, so if the BIOS does not set it back to full power mode in time,
       it will not be able to configure it correctly.  The driver tries to detect this condition and  bring  the
       adapter  back  to  the  D0 (full power) state, but this may not be enough to return the driver to a fully
       operational condition.  If you see this message at boot time and the driver fails to attach the device as
       a network interface, you will have to perform a warm boot to have the device properly configured.

       Note that this condition only occurs when warm booting from another operating system.  If you power  down
       your system prior to booting FreeBSD, the card should be configured correctly.

SEE ALSO

       arp(4), miibus(4), netintro(4), ng_ether(4), ifconfig(8)

       AMD PCnet/FAST, PCnet/FAST+ and PCnet/Home datasheets, http://www.amd.com.

HISTORY

       The pcn device driver first appeared in FreeBSD 4.3.

AUTHORS

       The pcn driver was written by Bill Paul <wpaul@osd.bsdi.com>.

Debian                                          January 31, 2006                                          PCN(4)