82801BA Datasheet, PDF (82/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

Functional Description
5.2.6
Media Management Interface
The management interface allows the processor to control the LAN Connect component via a
control register in the ICH2 integrated LAN Controller. This allows the software driver to place the
LAN Connect in specific modes such as 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 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 LAN
Connect component, and are described in detail in the 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 LAN Connect component through the MDI register.
5.2.7 TCO Functionality
The ICH2-M integrated LAN controller supports management communication to reduce Total Cost
of Ownership (TCO). It has a System Management Bus (SMB) on which the LAN controller is a
slave device. The SMB is used as an interface between the LAN controller and the integrated host
controller. An EEPROM of 256 words is required to support the heartbeat command.
Receive Functionality
In the power-up state, the LAN controller transfers TCO packets to the host as any other packet.
These packets include a new status indication bit in the Receive Frame Descriptor (RFD) status
register and have a specific port number indicating TCO packet recognition. In the power-down
state, the TCO packets are treated as wake-up packets. The ICH2-M integrated LAN controller
asserts the PME# signal and delivers the first 120 bytes of the packet to the host.
Transmit Functionality
The ICH2-M integrated LAN controller supports the Heartbeat (HB) transmission command from
the SMB interface. The send HB packet command includes a system health status issued by the
integrated system controller. The LAN controller computes a matched checksum and CRC and
transmits the HB packet from its serial EEPROM. The HB packet size and structure are not limited
as long as it fits within the EEPROM size. In this case, the EEPROM size is 256 words to enable
the storage of the HB packet (the first 64 words are used for driver specific data).
Note:
On the SMB, the send heartbeat packet command is not normally used in the D0 power state. The
one exception in which it is used in the D0 state is when the system is hung. In normal operating
mode, the heartbeat packets are transmitted through the ICH2-M integrated LAN controller
software similar to other packets.
5.3
LPC Bridge (w/ System and Management Functions)
(D31:F0)
The LPC Bridge function of the ICH2 resides in PCI Device 31:Function 0. In addition to the LPC
bridge function, D31:F0 contains other functional units including DMA, Interrupt Controllers,
Timers, Power Management, System Management, GPIO, and RTC. In this chapter, registers and
functions associated with other functional units (power management, GPIO, USB, IDE, etc.) are
described in their respective sections.
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82801BA ICH2 and 82801BAM ICH2-M Datasheet