82801FB Datasheet, PDF (111/786 Pages) Intel Corporation – Intel I/O Controller Hub 6 (ICH6) Family

Functional Description
5.3.3.2
5.3.3.3
5.3.4
5.3.5
5.3.5.1
Flow Control
The LAN controller supports IEEE 802.3x frame-based flow control frames only in both full
duplex and half duplex switched environments. The LAN controller flow control feature is not
intended to be used in shared media environments.
Flow control is optional in full-duplex mode and is selected through software configuration. There
are three modes of flow control that can be selected: frame-based transmit flow control, frame-
based receive flow control, and none.
VLAN Support
The LAN controller supports the IEEE 802.1 standard VLAN. All VLAN flows will be
implemented by software. The LAN controller supports the reception of long frames, specifically
frames longer than 1518 bytes, including the CRC, if software sets the Long Receive OK bit in the
Configuration command. Otherwise, “long” frames are discarded.
Media Management Interface
The management interface allows the processor to control the platform LAN Connect component
via a control register in the ICH6 integrated LAN controller. This allows the software driver to
place the platform LAN Connect in specific modes (e.g., full duplex, loopback, power down, etc.)
without the need for specific hardware pins to select the desired mode. This structure allows the
LAN controller to query the platform LAN Connect component for status of the link. This register
is the MDI Control Register and resides at offset 10h in the LAN controller CSR. The MDI
registers reside within the platform LAN Connect component, and are described in detail in the
platform LAN Connect component’s datasheet. The processor writes commands to this register and
the LAN controller reads or writes the control/status parameters to the platform LAN Connect
component through the MDI register.
TCO Functionality
The ICH6 integrated LAN controller supports management communication to reduce Total Cost of
Ownership (TCO). The SMBus is used as an interface between the ASF controller and the
integrated TCO host controller. There are two different types of TCO operation that are supported
(only one supported at a time), they are 1) Integrated ASF Control or 2) external TCO controller
support. The SMLink is a dedicated bus between the LAN controller and the integrated ASF
controller (if enabled) or an external management controller. An EEPROM of 256 words is
required to support the heartbeat command.
Advanced TCO Mode
The Advanced TCO functionalities through the SMLink are listed in Table 5-3.
Intel^® I/O Controller Hub 6 (ICH6) Family Datasheet
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