Intel PCI User Manual

153

The PCI/PCI-X Family of Gigabit Ethernet Controllers provide a complete CSMA/CD function 
supporting IEEE 802.3 (10Mb/s), 802.3u (100Mb/s), 802.3z and 802.3ab (1000Mb/s) 

implementations. They perform all of the functions required for transmission, reception and 

collision handling called out in the standards.

The internal Gigabit Media Independent Interface/Media Independent Interface (GMII/MII) 
supports the onboard 10/100/1000 BASE-T transceivers full duplex operation and supports the 

onboard 10/100 BASE-T transceivers in full or half duplex operation.

The 82541xx, 82547GI/EI, and 82540EP/EM do support SerDes functionality.

 and 82545GM/EM Ethernet controllers contain an internal 10-bit Fibre Channel 

Interface (TBI), as specified in IEEE 802.3z, for full-duplex operation with a SerDes transceiver. 
This configuration is applicable to 1000BASE-SX, -LX, or –CX links. When in internal SerDes 

mode, they provide the full Physical Coding Sub-layer implementation including Auto-Negotiation 

as called out in IEEE 802.3z.

 Ethernet controllers support a 10-bit TBI, as specified in IEEE 802.3z, for full-

duplex operation with a SerDes transceiver. This configuration is applicable to 1000BASE-SX, -

LX, or –CX links. When in TBI mode, they provide the full Physical Coding Sub-layer 

implementation including Auto-Negotiation as called out in IEEE 802.3z.

Selection between the various configurations is programmable via each MAC’s Extended Device 
Control Register (CTRL_EXT.LINK_MODE bits) and defaulted via EEPROM settings. Note that 

the external TBI interface is a single resource that can only be associated with a single MAC. 

The GMII/MII mode used to communicate between the MAC and the internal PHY supports 10/
100/1000 Mbps operation, with both half- and full-duplex operation at 10/100 Mbps, and full-

duplex operation at 1000 Mbps. 

The Ethernet controllers are optimized for full-duplex operation in 1000 Mbps mode. Half-duplex 

1000 Mbps operation is NOT supported and is not recommended. 

The internal copper PHY features 10/100/1000-BaseT signalling and is capable of performing 
intelligent power-management based on both the system power-state and LAN energy-detection 

(detection of unplugged cables). Power management includes ability to shut-down to extremely 

low (powered-down) state when not needed, as well as ability to auto-negotiate to lower-speed 
(and less power-hungry) 10/100 Mbps operation when the system is in low power-states.