- IPMI -
Intelligent Platform Management Bus
Communications Protocol Specification
v1.0
Document Revision 1.0
November 15, 1999
Intel Hewlett-Packard NEC Dell
Confidential
Intelligent Platform Management Bus Communications Protocol Specification
ii
Revision History
Date Ver Rev Modifications
9/16/98 1.0 1.0 Initial release.
11/15/99 1.0 1.0 Updated license agreement.
Copyright © 1998, 1999 Intel Corporation, Hewlett-Packard Company, NEC
Corporation, Dell Computer Corporation, All rights reserved.
INTELLECTUAL PROPERTY DISCLAIMER
THIS SPECIFICATION IS PROVIDED “AS IS” WITH NO WARRANTIES WHATSOEVER INCLUDING ANY
WARRANTY OF MERCHANTABILITY, FITNESS FOR ANY PARTICULAR PURPOSE, OR ANY WARRANTY
OTHERWISE ARISING OUT OF ANY PROPOSAL, SPECIFICATION, OR SAMPLE.
NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY
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INTEL, HEWLETT-PACKARD, NEC, AND DELL DISCLAIM ALL LIABILITY, INCLUDING LIABILITY FOR
INFRINGEMENT OF PROPRIETARY RIGHTS, RELATING TO IMPLEMENTATION OF INFORMATION IN THIS
SPECIFICATION. INTEL, HEWLETT-PACKARD, NEC, AND DELL, DO NOT WARRANT OR REPRESENT THAT
SUCH IMPLEMENTATION(S) WILL NOT INFRINGE SUCH RIGHTS.
I
2
C is a trademark of Philips Semiconductors. All other product names are trademarks, registered trademarks, or servicemarks
of their respective owners.
I
2
C is a two-wire communications bus/protocol developed by Philips. IPMB is a subset of the I
2
C bus/protocol and was
developed by Intel. Implementations of the I
2
C bus/protocol or the IPMB bus/protocol may require licenses from various
entities, including Philips Electronics N.V. and North American Philips Corporation.
Intel, Hewlett-Packard, NEC, and Dell retain the right to make changes to this document at any time, without notice. Intel,
Hewlett-Packard, NEC, and Dell make no warranty for the use of this document and assumes no responsibility for any error
which may appear in the document nor does it make a commitment to update the information contained herein.
Intelligent Platform Management Bus Communications Protocol Specification
iii
LIMITED RELEASE SPECIFICATIONS LICENSE AGREEMENT
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Management Interface Specification (v1.0), Intelligent Platform Management Bus Bridge Specification (v 1.0), and
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Intelligent Platform Management Bus Communications Protocol Specification
iv
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Intelligent Platform Management Bus Communications Protocol Specification
v
Table of Contents
1. Introduction...........................................................................................................1
1.1 Audience....................................................................................................................................1
1.2 Reference Documents .................................................................................................................2
1.3 Conventions, Terminology, and Notation.....................................................................................3
1.4 Scope.........................................................................................................................................5
1.5 Background................................................................................................................................5
1.6 Platform Management Network Topology...................................................................................6
1.7 Application of the Protocol.........................................................................................................8
1.7.1 Scale...................................................................................................................................8
1.8 Request / Response Protocol.......................................................................................................9
1.9 Service Model Definition............................................................................................................9
1.10 Design Objectives.......................................................................................................................9
1.11 Protocol Use of I
2
C Services.......................................................................................................9
2. Functional Specification ....................................................................................13
2.1 Request / Response Mechanism................................................................................................13
2.2 Terminology.............................................................................................................................13
2.3 Directing responses back to the Requester.................................................................................15
2.4 Telling Requests from Responses..............................................................................................15
2.5 Responding to Requests............................................................................................................15
2.5.1 Corrupted Request Handling..............................................................................................16
2.6 Missing Response Handling (retries).........................................................................................16
2.6.1 The Seq Field and Retries ..................................................................................................16
2.6.2 Seq Value Expiration.........................................................................................................17
2.7 Response Time-outs .................................................................................................................17
2.8 Unexpected Request Messages..................................................................................................17
2.9 Bad and Unexpected Response Messages..................................................................................18
2.10 Link Layer Addressing .............................................................................................................18
2.10.1 Connection Header ............................................................................................................18
2.10.2 Non-intelligent Device Slave Addressing............................................................................18
2.10.3 Slave Address Specification...............................................................................................19
2.11 Message Transaction Formats...................................................................................................19
2.11.1 IPMB Node to Node Transactions......................................................................................19
3. Network Functions and Commands..................................................................20
3.1 Completion Codes ....................................................................................................................21
3.2 Application Messages (netFn 06, 07)........................................................................................21
3.3 Sensor/Event Messages (netFn 04, 05)......................................................................................21
3.3.1 Event Messages.................................................................................................................21
3.3.2 Sensor Messages ...............................................................................................................22
3.4 Firmware Messages (netFn 07, 08) ...........................................................................................22
3.5 Storage Messages (netFn 0A, 0B).............................................................................................22
3.6 Bridge Messages (netFn 02, 03)................................................................................................23
3.7 Chassis Device Messages (netFn 00, 01)...................................................................................23
