MSPM0 PMBus Library User’s Guide

1. Introduction

The MSPM0 PMBus Library is based on the MSPM0 SMBus library. The MSPM0 PMBus library provides a set of APIs to communicate over PMBus as a controller or a target.

2. PMBus Library Supported Features

This library was developed in compliance with the PMBus 1.3.1 specification.

2.1 PMBus Supported Features

• Address, memory, communication and capability related commands

• On, off, and margin testing related commands

• Output voltage related commands

• “Other commands” as detailed by the PMBus specification

• Fault related commands

• Power good signal limits

• Output voltage sequencing commands

• Unit status commands

• Parametric information commands

• Manufacturer’s information commands

2.3 PMBus Features Not Currently Implemented

The PMBus features listed below are supported in hardware but have not been implemented in this release:

• ZONE_READ and ZONE_WRITE protocols

3. PMBus Example Usage

Three examples are given in the SDK demonstrating the PMBus controller , PMBus target and PMBus controller using group command.

To test the PMBus controller and target example connect the SDL and SDA pins of controller and target. Load the program to controller and target. The example services the following commands.

PMBus CMD	CMD ID	Write Type	Read Type
Device ID	0xAD		Block read
Clear Faults	0x03	Send Byte
Vout Mode	0x020	Write Byte	Read Byte
Vout OV warn Limit	0x42	Write Word	Read Word
MRF ID	0x99	Block Write	Block Read
Read Vout	0x8B		Read Word
EXT_BYTE_CMD	0x01FF	Write Byte	Read Byte
EXT_WORD_CMD	0x02FF	Write Word	Read Word
Process call Byte	0xD0	Write Word	Read Word
Process call Block	0xD1	Block Write	Block Read

To test the group command, load the target examples to 2 launchpads with different slave addresses specified in the group commamnd examples. The group command example will communicate with both targets and service the PMBus comamnds.

3.1 PMBus Examples Supported Hardware

• LP-MSPM0G3519 or LP-MSPM0G3507 LaunchPad evaluation boards

4. Library Versions

• Version 2.00.00.00

  • SDK release: 2.04.00.xx

  • Updates:

    • Updated PMBus stack to support both as controller and target.

    • Added PMBus controller and target examples.

    • Added PMBus controller to support group commands.

• Version 1.11.01.00

  • SDK Release: 2.03.00.xx

  • Updates:

    • Fix PMB_BLOCK_READ #define

• Version 1.10.00.00

  • SDK Release: 1.30.00.xx

  • Updates:

    • Updates to use SMBus 1.30.00.xx.

    • Remove unimplemented PMBus_processTimeoutInt.

    • Update examples to use I2C boosterPack standard.

• Version 1.00.00.01

  • SDK Release: 1.10.00.xx

  • Updates:

    • Initial release.