Management Component Transport Protocol (MCTP) …

1 1 Document Number: DSP0237 2 Date: 2017-05-21 3 Version: 4 Management Component Transport Protocol 5 (MCTP) SMBus/I2C Transport Binding 6 Specification 7 Supersedes: 8 Document Class: Normative 9 Document Status: Published 10 Document Language: en-US 11 MCTP SMBus/I2C Transport Binding Specification DSP0237 2 Published Version 12 Copyright Notice 13 Copyright 2017 Distributed Management Task Force, Inc. (DMTF). All rights reserved. 14 DMTF is a not-for-profit association of industry members dedicated to promoting enterprise and systems 15 Management and interoperability. Members and non-members may reproduce DMTF specifications and 16 documents, provided that correct attribution is given.

2 As DMTF specifications may be revised from time to 17 time, the particular version and release date should always be noted. 18 Implementation of certain elements of this standard or proposed standard may be subject to third party 19 patent rights, including provisional patent rights (herein "patent rights"). DMTF makes no representations 20 to users of the standard as to the existence of such rights, and is not responsible to recognize, disclose, 21 or identify any or all such third party patent right, owners or claimants, nor for any incomplete or 22 inaccurate identification or disclosure of such rights, owners or claimants.

3 DMTF shall have no liability to 23 any party, in any manner or circumstance, under any legal theory whatsoever, for failure to recognize, 24 disclose, or identify any such third party patent rights, or for such party s reliance on the standard or 25 incorporation thereof in its product, protocols or testing procedures. DMTF shall have no liability to any 26 party implementing such standard, whether such implementation is foreseeable or not, nor to any patent 27 owner or claimant, and shall have no liability or responsibility for costs or losses incurred if a standard is 28 withdrawn or modified after publication, and shall be indemnified and held harmless by any party 29 implementing the standard from any and all claims of infringement by a patent owner for such 30 implementations.

4 31 For information about patents held by third-parties which have notified the DMTF that, in their opinion, 32 such patent may relate to or impact implementations of DMTF standards, visit 33 34 PCI-SIG, PCIe, and the PCI HOT PLUG design mark are registered trademarks or service marks of PCI-35 SIG. 36 All other marks and brands are the property of their respective owners. 37 38 DSP0237 MCTP SMBus/I2C Transport Binding Specification Version Published 3 CONTENTS 39 Foreword .. 5 40 6 41 1 Scope .. 7 42 2 Normative references .. 7 43 3 Terms and definitions .. 7 44 4 Symbols and abbreviated terms .. 8 45 5 Conventions.

5 10 46 Reserved and unassigned values .. 10 47 Byte ordering .. 11 48 6 MCTP over SMBus/I2C Transport .. 11 49 Terminology .. 11 50 Transport binding use with I2C .. 12 51 MCTP packet encapsulation .. 12 52 Bridges and packet formatting .. 13 53 MCTP support 13 54 Support for fixed-address devices .. 14 55 Supported media .. 14 56 Physical address format for MCTP control messages .. 15 57 Get endpoint ID Medium-Specific Information .. 15 58 Bus owner address .. 15 59 Bus address assignment .. 15 60 SMBus/I2C considerations for MCTP messages .. 19 61 Fairness arbitration .. 20 62 NACK window.

6 21 63 Fairness arbitration requirements for MCTP bridges .. 22 64 Fairness arbitration requirements for non-bridge endpoints .. 23 65 Fairness arbitration timing .. 24 66 MCTP packet timing requirements .. 25 67 MCTP control message timing 27 68 "Stuck 0" condition handling .. 28 69 MCTP over SMBus/I2C Protocol anti-aliasing .. 29 70 Well-known and reserved slave addresses .. 30 71 Fixed address allocation .. 31 72 Recommended address range allocation for computer systems .. 32 73 ANNEX A (informative) Notation .. 35 74 ANNEX B (informative) Change log .. 36 75 76 Figures 77 Figure 1 MCTP over SMBus/I2C packet format.

7 12 78 Figure 2 Address assignment flow .. 18 79 Figure 3 Allowed byte range for first NACK'd byte .. 21 80 Figure 4 Fairness arbitration timing measurement for SMBus and I2C .. 24 81 Figure 5 Example system configuration .. 32 82 83 MCTP SMBus/I2C Transport Binding Specification DSP0237 4 Published Version Tables 84 Table 1 Packet header field descriptions .. 12 85 Table 2 Supported media .. 15 86 Table 3 Physical address format .. 15 87 Table 4 Medium-Specific Information .. 15 88 Table 5 Fairness arbitration timing values for 100 kHz SMBus/I2C .. 24 89 Table 6 Fairness arbitration timing values for 400 kHz I2C.

8 25 90 Table 7 Fairness arbitration timing values for 1 MHz 25 91 Table 8 Timing specifications for MCTP packets on SMBus/I2C .. 26 92 Table 9 Timing Specifications for MCTP control messages on SMBus .. 27 93 Table 10 Well-known and reserved slave addresses .. 30 94 Table 11 Slave address allocation for computer systems .. 33 95 96 DSP0237 MCTP SMBus/I2C Transport Binding Specification Version Published 5 Foreword 97 The Management Component Transport Protocol (MCTP) SMBus/I2C Transport Binding Specification 98 (DSP0237) was prepared by the PMCI Subgroup of the Pre-OS Working Group. 99 DMTF is a not-for-profit association of industry members dedicated to promoting enterprise and systems 100 Management and interoperability.

9 101 Acknowledgments 102 The DMTF acknowledges the following individuals for their contributions to this document: 103 Editor: 104 Yuval Itkin mellanox technologies 105 Contributors: 106 Alan Berenbaum SMSC 107 Klodnicki Edward - IBM 108 Kozlowski Koe Dell Inc 109 Patrick Caporale Lenovo 110 Patrick Schoeller Hewlett Packard Enterprise 111 Phil Chidester Dell Inc 112 John Leung - Intel Corporation 113 Eliel Louzoun Intel Corporation 114 Hemal Shah - Broadcom Limited 115 Tom Slaight Intel Corporation 116 Yi Zeng Intel Corporation 117 118 MCTP SMBus/I2C Transport Binding Specification DSP0237 6 Published Version Introduction 119 The Management Component Transport Protocol (MCTP)

10 Over SMBus/I2C Transport binding defines a 120 Transport binding for facilitating communication between platform Management subsystem components 121 ( , Management controllers, managed devices) over SMBus/I2C. 122 The MCTP Base Specification (MCTP) describes the Protocol and commands used for communication 123 within and initialization of an MCTP network. The MCTP over SMBus/I2C Transport binding definition in 124 this specification includes a packet format, physical address format, message routing, and discovery 125 mechanisms for MCTP over SMBus/I2C communications. 126 127 DSP0237 MCTP SMBus/I2C Transport Binding Specification Version Published 7 Management Component Transport Protocol (MCTP) 128 SMBus/I2C Transport Binding Specification 129 1 Scope 130 This document provides the specifications for the Management Component Transport Protocol (MCTP) 131 Transport binding for SMBus/I2C.