JME(4)							   BSD Kernel Interfaces Manual 						    JME(4)

NAME

     jme -- JMicron Technologies JMC250 Gigabit Ethernet and JMC260 Fast Ethernet controller driver

SYNOPSIS

     jme* at pci? dev ? function ?

     Configuration of PHYs is necessary.  See mii(4).

DESCRIPTION

     The jme device driver supports network adapters based on the JMicron Technologies JMC250 Gigabit Ethernet and JMC260 Fast Ethernet chips.
     The following features are supported:

	   IPv4 transmit/receive IP/TCP/UDP checksum offload
	   IPv6 transmit TCP/UDP checksum offload
	   IPv4 and IPv6 TCP segmentation offload
	   VLAN tag insertion/removal
	   Interrupt coalescing
	   10/100/1000Mbps operation in full-duplex mode
	   10/100Mbps operation in half-duplex mode
	   Jumbo frames (up to 9022 bytes)

     Due to hardware limitation checksums and TCP segmentation offload can't be enabled if the configured MTU is larger than 4000 bytes.

     Interrupt coalescing can be controlled on a per-adapter basis through the following sysctls:

     hw.jme.jme<x>.int_rxtos  jme receive interrupt moderation timer, in microseconds (defaults to 100)

     hw.jme.jme<x>.int_rxct   jme receive interrupt moderation packet counter (defaults to 128)

     hw.jme.jme<x>.int_txto   jme transmit interrupt moderation timer, in microseconds (defaults to 100)

     hw.jme.jme<x>.int_txct   jme transmit interrupt moderation packet counter (defaults to 128)

SEE ALSO

     ifmedia(4), mii(4), netintro(4), pci(4), ifconfig(8)

HISTORY

     The jme device driver first appeared in NetBSD 5.0.

BUGS

     Hardware bugs prevent support of IPv6 receive TCP/UDP checksum offload in the JMC250 rev A2, and is disabled in the driver.  This should be
     revisited when a newer hardware revision is available.

BSD
								 October 17, 2008							       BSD