home | help 
PCN(4)			     Kernel Interfaces Manual			  PCN(4)

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 con-
     trollers  based  on  the  AMD  PCnet/FAST, PCnet/FAST+, PCnet/FAST III, PC-
     net/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 ser-
     ial 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.  Re-
     ceive 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 Eth-
     ernet 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 oc-
     curred.

     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 operat-
     ing 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>.

FreeBSD 7.0			January 31, 2006			  PCN(4)
home | help