Intel SDS2 - Manual (Page 22)

Processor and Chipset Intel® Server Board SDS2
Revision 1.2
Order Number: A85874-002
8
3.2.2 I
2
C Bus
An I
2
C* bus is between the BMC and the six DIMM slots. This bus is used by the system BIOS to
retrieve DIMM information needed to program the HE-SL memory registers which are required to
boot the system.
The following table provides the I
2
C addresses for each DIMM slot.
Table 3. I 2 C Addresses for DIMM Slots
Device Address
DIMM 1A 0xA0
DIMM 1B 0xA2
DIMM 2A 0xA4
DIMM 2B 0xA6
DIMM 3A 0xA8
DIMM 3B 0xAA
3.3 Chipset
The Server Works* ServerSet III HE-SL chipset provides an integrated I/O bridge and memory
controller and a flexible I/O subsystem core (PCI), targeted for multiprocessor systems and
standard high-volume servers. The Server Works* ServerSet III chipset consists of the three
components listed below:
• CNB20HE-SL: Champion North Bridge. The HE-SL North Bridge is responsible for
accepting access requests from the host (processor) bus and for directing those
accesses to memory or to one of the PCI buses. The HE-SL monitors the host bus,
examining addresses for each request. Accesses may be directed to a memory request
queue, for subsequent forwarding to the memory subsystem, or to an outbound request
queue, for subsequent forwarding to one of the PCI buses. The HE-SL also accepts
inbound requests from the CIOB20 and the legacy PCI bus. The HE-SL is also
responsible for generating the appropriate controls to control data transfer to and from
the memory.
• CIOB20: Champion I/O Bridge. The CIOB20 provides the interface for two 64-bit, 66-
MHz Rev. 2.2 compliant PCI bus. The CIOB is both master and target on both PCI
buses.
• CSB5: South Bridge. The CSB5 controller has several components. It provides the
interface for a 32-bit, 33-MHz Rev. 2.2-compliant PCI bus. The CSB5 can be both a
master and a target on that PCI bus. The CSB5 also includes a USB controller and an
IDE controller. The CSB5 is also responsible for much of the power management
functions, with ACPI control registers built in. The CSB5 also provides a number of GPIO
pins and has the LPC bus to support low-speed legacy I/O.