Ipmb Communication Interface - Intel S7000FC4UR Technical Product Specification

Intel® Server System S7000FC4UR TPS
The host I/O address of the SMM interface is nominally 0CA4h – 0CA5h, but this address
assignment may be overridden by the platform-specific section of the appendix.

23.2 IPMB Communication Interface

The IPMB communication protocol uses the 100 KB/s version of an I
medium. For more information on I
IPMB implementation in the BMC is compliant with the IPMB v1.0, revision 1.0.
The BMC IPMB slave address is 20h.
The BMC both sends and receives IPMB messages over the IPMB interface. Non-IPMB
messages received via the IPMB interface are discarded.
Messages sent by the BMC can be either originated by the BMC, such as when due to
initialization agent operation, or on behalf of another source, such as due to a Send Message
command with IPMB channel number issued by SMS.
For IPMB request messages originated by the BMC, the BMC implements a response timeout
interval of 60 ms and a retry count of 3.
23.3 IPMI Serial Feature
The IPMI 2.0 Intel implementation of IPMI-over-serial was known before IPMI 1.0 as the
emergency management port (EMP) interface. The EMP nomenclature is no longer used.
The primary goal of providing an out-of-band RS232 connection is to give system administrators
the ability to access low-level server management firmware functions by using commonly
available tools. To make it easy to use and to provide high-compatibility with LAN and IPMB
protocols, this protocol design adopts some features of both the LAN and IPMB protocols.
The Intel implementation shares EMP function with the platform's COM2 interface. The BMC
has control over which agent (BMC or System) has access to COM2. Hardware handshaking is
supported as are the Ring Indicate and Data Carrier Detect signals.
See the IPMI 2.0 specification.
23.3.1 COM Port Switching
The SIO3 (formerly National Semiconductor* 87427) is used for Com port sharing. It has two
legacy UARTS and a MUX switching arrangement that permits the BMC to monitor and
intercept the serial traffic on serial port 2.
If IPMI-over-serial is enabled, then the BMC watches the serial traffic when serial port 2, the
COM2 port, is owned by the system. This is done to respond to in-band port switching requests.
23.3.2 Terminal Mode
The BMC supports terminal mode, as specified in the IPMI 2.0 specification. Terminal mode
provides a printable ASCII text-based way to deliver IPMI messages to the BMC over the serial
channel or any packet-based interface. Messages can be delivered in two forms:
Revision 1.0
2
C specifications, see The I2C Bus and How to Use It. The
BMC Messaging Interfaces
2
C bus as its physical
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