PMBUS规格书1.2I

【实例截图】

【核心代码】

Table Of Contents
1 Introduction ............................................................................................................................................ 5
1.1 Specification Scope ........................................................................................................................ 5
1.1.1 Specification Structure ............................................................................................................ 5
1.1.2 What Is Included ...................................................................................................................... 5
1.1.3 What Is Not Included In The PMBus Specification.................................................................. 5
1.2 Specification Changes Since The Last Revision ............................................................................ 5
1.3 Where To Send Feedback And Comments .................................................................................... 5
2 Related Documents ............................................................................................................................... 5
2.1 Scope .............................................................................................................................................. 5
2.2 Applicable Documents .................................................................................................................... 5
2.3 Reference Documents .................................................................................................................... 6
3 Reference Information ........................................................................................................................... 6
3.1 Signal and Parameter Names ........................................................................................................ 6
3.2 Numerical Formats ......................................................................................................................... 6
3.2.1 Decimal Numbers .................................................................................................................... 6
3.2.2 Binary Numbers ....................................................................................................................... 6
3.2.3 Hexadecimal Numbers ............................................................................................................ 6
3.2.4 Examples ................................................................................................................................. 6
3.3 Byte And Bit Order .......................................................................................................................... 7
3.4 Bit And Byte Illustrations ................................................................................................................. 7
3.5 Abbreviations, Acronyms And Definitions....................................................................................... 8
4 General Requirements ......................................................................................................................... 11
4.1 Compliance ................................................................................................................................... 11
4.2 Unassisted Start Up And Operation ............................................................................................. 11
5 Transport .............................................................................................................................................. 11
5.1 SMBus, Version 2.0 ...................................................................................................................... 11
5.2 Extensions To The SMBus, Version 2.0 Specification ................................................................. 12
5.2.1 Deleted .................................................................................................................................. 12
5.2.2 Deleted .................................................................................................................................. 12
5.2.3 Group Command Protocol ..................................................................................................... 12
5.2.4 Extended Command: Read/Write Byte ................................................................................. 13
5.2.5 Extended Command: Read/Write Word ................................................................................ 14
5.2.6 Bus Speed ............................................................................................................................. 15
5.2.6.1 100 kHz .......................................................................................................................... 15
5.2.6.2 400 kHz .......................................................................................................................... 15
5.2.7 Electrical Drive Levels ........................................................................................................... 16
5.2.8 High Impedance When Unpowered ...................................................................................... 16
5.3 Exceptions To The SMBus, Version 2.0 Specification ................................................................. 16
5.3.1 Block Size .............................................................................................................................. 16
5.3.2 SMBus Address Resolution Protocol (ARP) ......................................................................... 17
6 Addressing ........................................................................................................................................... 17
7 Packet Error Checking ......................................................................................................................... 17
8 Communication From PMBus Devices To The Host ........................................................................... 17
8.1 Communicating Over The Bus ..................................................................................................... 17
8.2 Communicating With An Interrupt Signal ..................................................................................... 17
9 Hardwired Signals ................................................................................................................................ 17
9.1 Electrical Interface ........................................................................................................................ 17
9.2 Timing ........................................................................................................................................... 17
9.3 Control Signal (CONTROL) .......................................................................................................... 18
9.4 Write Protect (WP) ........................................................................................................................ 18
9.5 Other Pins ..................................................................................................................................... 18
10 Accuracy ........................................................................................................................................... 18
11 Firmware Updates ............................................................................................................................ 18
12 Summary Of Changes ...................................................................................................................... 19
PMBus™ Power System Mgt Protocol Specification – Part I – Revision 1.2X
©2010 System Management Interface Forum, Inc. Page 4 of 19
All Rights Reserved
Table Of Figures
Figure 1. Bit Order Within A Byte .................................................................................................................. 7
Figure 2. Group Command Protocol Without PEC ..................................................................................... 13
Figure 3. Group Command Protocol With PEC .......................................................................................... 13
Figure 4. Extended Command Read Byte Protocol .................................................................................... 14
Figure 5. Extended Command Read Byte With PEC ................................................................................. 14
Figure 6. Extended Command Write Byte Protocol .................................................................................... 14
Figure 7. Extended Command Write Byte Protocol With PEC ................................................................... 14
Figure 8. Extended Command Read Word Protocol .................................................................................. 14
Figure 9. Extended Command Read Word Protocol With PEC .................................................................. 15
Figure 10. Extended Command Write Word Protocol ................................................................................. 15
Figure 11. Extended Command Write Word Protocol With PEC ................................................................ 15
Table Of Tables
Table 1. Bit And Byte Symbols Used In This Specification ........................................................................... 7
Table 2. Timing Parameters For Higher Speed Operation ......................................................................... 15