1 intelligent platform management buses (ipmb), 3 inter-chassis management bus (icmb) – Intel SE8500HW4 User Manual
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Server Management
Intel® Server Board Set SE8500HW4
Revision
1.0
Intel order number D22893-001
38
5.6.1
Intelligent Platform Management Buses (IPMB)
The IPMB is a communication protocol that utilizes a 100 KB/s I
2
C bus. The IPMB
implementation in the BMC is compliant with the IPMB v1.0, revision 1.0, with the BMC having
an IPMB slave address of 0x20.
The BMC both sends and receives IPMB messages over the IPMB interface. Non-IPMB
messages received via the IPMB interface are discarded. In addition to the public IPMB, the
BMC has six private I
2
C buses that extend throughout the system. Table 14 shows all the I
2
C
buses in the Intel
®
Server Board Set SE8500HW4 and Intel
®
Server Platform
SR4850HW4/SR6850HW4, and Figure 8 shows a graphical representation of these buses.
Table 14. Platform I
2
C Buses
Physical
I
2
C Bus #
Active with
Standby
Power Only
Private
Bus ID
Logical
I
2
C Bus ID
Bus Name
Devices Connected
0 Y
- 0 IPMB
Hot Swap Controllers, IPMB Aux
connector, LCD Module
1
Y
-
2
PCI
PCI Bus slots
2 Y
2 5 IO
PCA9555, LM93 (2), LM75, FRU,
Power Distribution Board, Power
Supply Units (2)
3 N
3 7 CS
XMB (4), FC module, NB, PXH,
Intel
®
IOP332 Storage I/O Processor
4 Y
4 9 Processors
Processors
(4)
5 Y
5 B NIC
On-board
Networking
5.6.2
Keyboard Controller Style (KCS)/Low Pin Count (LPC) Bus
The BMC has three KCS interface ports as described in the IPMI 2.0 specification. These
interfaces are used to communicate SMI handling for error logging, BIOS POST, utility access
and power management communication. The BMC also acts as a bridge between the SMS and
IPMB interfaces.
5.6.3
Inter-Chassis Management Bus (ICMB)
The Intelligent Chassis Management Bus (ICMB) defines a character-level transport for inter-
chassis communications between intelligent chassis. This includes the ability to use the ICMB to
bridge messages from the IPMB in one chassis to the IPMB in another. At any given time, only
one chassis can be driving the bus. Each must arbitrate to gain control of the bus when it has
something to send. ICMB messages are IPMI compatible with an implicit net function of bridge.
Refer to Intelligent Chassis Management Bus, Version 1.0, Revision 1.20 for the definition of
commands and responses. The Intel
®
Server Board Set SE8500HW4 provides the ICMB
interface as an add-in transceiver card connected to the 5-pin ICMB header.