AN2511 Application Note - STMicroelectronics
AN2511Application notePMBusTM interface using ST7 I2CIntroductionThe PMBusTM (power management bus) is an open standard protocol that defines a meansof communicating with power conversion and other devices. The PMBus protocol helps toestablish the first truly open communications standard for the digital control of powersystems. Implemented over the industry-standard SMBus (system management bus) serialinterface, the PMBus protocol facilitates the programming, control and real-time monitoringof compliant power conversion products.This application note describes how to use the ST7 I2C peripheral for PMBuscommunication. The firmware of this application performs the PMBus bus protocolsmentioned in PMBusTM power system management protocol specification v1.0. The devicechosen here is ST72264G1 which has multi-master I2C capability. This microcontroller actsas the PMBus master. It controls the PMBus compatible slaves. The firmware described inthis application note is in C language.To show the PMBus capabilities of ST7, a dedicated demonstration board is developed. Thisboard consists of the ST72F264G1 microcontroller and it works with PC hyperterminal. Theobjective of this demonstration board is to show to the user the features and capabilities ofPMBus features using ST7 I2C peripheral, to support the standard PMBus commands. Theresults of this demonstration board interfaced with Artesyn's PMBus module are shown inthis application note.August 2010Doc ID 13286 Rev 21/43www.st.com
ContentsAN2511Contents1PMBus introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.11.22456SMBus version 1.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.1.2Extensions to SMBus version 1.1 specification . . . . . . . . . . . . . . . . . . . . 6Hardwired signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.2.1Electrical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.2.2Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Firmware architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.1.1I2C initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.1.2Slave address and command code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.1.3Read and write operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9PMBus commands and source code . . . . . . . . . . . . . . . . . . . . . . . . . . . 113.1PMBus commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113.2Source code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.3Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223.4Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23PMBus interfacing results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244.1Interfacing with Artesyn module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244.2Interfacing with SiLabs module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25PMBus demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275.1System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275.2Software setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275.3Hardware setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Using the demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306.12/431.1.1Implementation of PMBus using ST7 I2C . . . . . . . . . . . . . . . . . . . . . . . . 82.13PMBus protocol description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Normal operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306.1.1Selection of communication speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306.1.2Selection of packet error checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Doc ID 13286 Rev 2
AN2511Contents6.276.1.3Selection of slave address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306.1.4Selection of read/write mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316.1.5Single read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316.1.6Continuous read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326.1.7Write mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326.1.8Group command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Error conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346.2.1Invalid command code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346.2.2Communication timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Hardware description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367.1Schematic and layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367.2Bill of materials (BOM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387.3Demonstration board photo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Appendix A Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41A.1RS232 configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Doc ID 13286 Rev 23/43
List of tablesAN2511List of tablesTable 1.Table 2.Table 3.Table 4.Table 5.Table 6.Table 7.Table 8.Table 9.Table 10.Table 11.Table 12.Table 13.Table 14.Table 15.Table 16.Table 17.Table 18.Table 19.Table 20.Table 21.Table 22.Table 23.Table 24.Table 25.Table 26.Table 27.Table 28.Table 29.Table 30.Table 31.Table 32.Table 33.Table 34.Table 35.Table 36.Table 37.Table 38.Table 39.Table 40.Table 41.Table 42.Table 43.Table 44.4/43Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11ON OFF CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11CLEAR FAULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11RESTORE DEFAULT ALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12STORE USER ALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12VOUT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12VOUT COMMAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13VOUT MAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13VOUT MARGIN HIGH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13VOUT MARGIN LOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13VOUT OV WARN LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13VOUT UV WARN LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14IOUT OC FAULT LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14IOUT OC WARN LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14OT FAULT LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14OT FAULT RESPONSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15OT WARN LIMIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15TON DELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15TON RISE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15TOFF DELAY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15TOFF FALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16STATUS BYTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16STATUS WORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16STATUS VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16STATUS IOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17STATUS TEMPERATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17STATUS MFR SPECIFIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18READ VOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18READ IOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18READ TEMPERATURE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18PMBUS REVISION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19MFR ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19MFR MODEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19MFR REVISION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19MFR LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20MFR DATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20MFR SERIAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20MFR SPECIFIC 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20MFR SPECIFIC 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21MFR SPECIFIC 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21PMBus interfacing with Artesyn module: results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24PMBus interfacing with SiLabs module: results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Doc ID 13286 Rev 2
AN2511List of figuresList of figuresFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9.Figure 10.Figure 11.Figure 12.Figure 13.Figure 14.Figure 15.Figure 16.Figure 17.Figure 18.Figure 19.Figure 20.Figure 21.Figure 22.Figure 23.Figure 24.Figure 25.Figure 26.Figure 27.Figure 28.Figure 29.Figure 30.Interface diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Flowchart: I2C initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Flowchart: data length calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Flowchart: read operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Flowchart: write operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10PC hyperterminal application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Baud rate configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Hyperterminal settings - ASCII setup configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Hyperterminal message to show company name and selection of communication speed 30PEC selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Slave address entry message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Wrong slave address entry - response 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Wrong slave address entry - response 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Options to select read/ write mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Single read operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Continuous read operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Write mode command code entry message from hyperterminal . . . . . . . . . . . . . . . . . . . . 32Write mode data entry message from hyperterminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Write mode operation example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Read operation to check data writing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Group command code entry message from hyperterminal. . . . . . . . . . . . . . . . . . . . . . . . . 34Group command operation example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Invalid command message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Example of invalid command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Communication timeout message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Demonstration board schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Top view layout of the demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37Bottom view layout of the demonstration board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37STEVAL-ISQ002V1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Pin description of RS232 D9 connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Doc ID 13286 Rev 25/43
PMBus introductionAN25111PMBus introduction1.1PMBus protocol descriptionThe PMBus protocol is intended to cover a wide range of power system architectures andconverters.PMBus devices must use the system management bus (SMBus), version 1.1. Implementedover the industry-standard SMBus serial interface, the PMBus protocol facilitates theprogramming, control and real-time monitoring of compliant power conversion products.1.1.1SMBus version 1.1The system management bus (SMBus) is a two-wire interface through which various systemcomponent chips can communicate with each other and with the rest of the system. It isbased on the principles of operation of I2C.For more information about SMBus, refer to AN1713, available from www.st.com.1.1.2Extensions to SMBus version 1.1 specification1.Block write-block-read process callTo support certain commands of the PMBus command language, PMBus devices mustsupport the "Block write-block-read process call" described in Section 5.5.8 of Version2.0 of the SMBus Specification.2.Host notify protocolPMBus devices may support the host notify protocol described in Section 5.5.9 ofVersion 2.0 of the SMBus Specification. If a PMBus device supports the host notifyprotocol, the two data bytes sent to the host are the same as the data bytes returned bythe STATUS WORD command.3.Group command protocolPMBus devices must support the group command protocol. The group commandprotocol is used to send commands to more than one PMBus device. The commandsare received in one transmission. When the devices detect the STOP condition thatends the command, they all begin executing the command they received.4.AddressingPMBus devices use seven bit addresses.5.Packet error checking (PEC)Support for the SMBus packet error checking (PEC) protocol is optional.1.2Hardwired signals1.2.1Electrical interfaceThe following diagram shows the interface between different PMBus devices. ST72264G1 isthe selected microcontroller, which has a multi-master I2C interface. This microcontrolleracts as PMBus master. It communicates with any compatible PMBus slave using a 4-pininterface. SMBC is the clock from the master. SMBD is the data pin. Both SMBC and SMBDshould be pulled up with a 4.7 kΩ resistor. SMBALERT is the SMBus alert pin, which helps6/43Doc ID 13286 Rev 2
AN2511PMBus introductionthe slave to alert the master whenever it wants to communicate. The control pin is used toswitch ON or OFF a PMBus slave.Figure 1.Interface diagramPMBus MasterPMBus Slave(ST72F264G1)SMBC (SCL)SMBD (SDA)SMBCSMBDSMBA (PA3)CONTROL (PC0)SMBACONTROLThe CONTROL signal is an input signal on a power converter. It is used to turn the unit onand off in conjunction with commands received via the serial bus. It can be configured as anactive high or active low signal through the ON OFF CONFIG command (refer toSection 3.1).This signal is optional but recommended.1.2.2TimingNo specific requirements are made when a PMBus device must respond to a state changeof a hardwired signal.Doc ID 13286 Rev 27/43
Implementation of PMBus using ST7 I2CAN25112Implementation of PMBus using ST7 I2C2.1Firmware architectureThis section explains sequence of operation for different software modules.2.1.1I2C initializationTo use ST7 I2C for PMBus communication, the peripheral is initialized for 100 kHzcommunication speed. The I2C is configured with an address of 0x30, as it can act as aslave due to its multi-master capability. The following flowchart shows the sequence.Figure 2.Flowchart: I2C initializationSTARTInitialize I2C CR, CCR,OAR1 and OAR2 registersConfigure slave addressesin OAR1 and OAR2Enable I2C peripheral andacknowledge in I2CCR registerSet communication speed as100kHz in I2CCCR registerSTOPThe above flowchart is implemented in the function PMBus Init.2.1.2Slave address and command codeThe PMBus master addresses the slave with a 7-bit address. Once the slave deviceacknowledges the address, the command code is sent corresponding to the PMBuscommand and SMBus protocol (refer to Section 3.1).Then, the microcontroller decodes the command code as shown in the following sequence.Simultaneously, the SMBus Mode variable is updated.8/43Doc ID 13286 Rev 2
AN2511Implementation of PMBus using ST7 I2CFigure 3.Flowchart: data length calculationSTARTByte Count 6,UpdateSMBus Modefor Block CommandYesCheck if command code equalto Block protocolNoByte Count 1,UpdateSMBus Modefor Byte CommandYesCheck if command code equalto Byte protocolNoYesCheck if command code equalto word protocolByte Count 2,UpdateSMBus Modefor Word CommandNoSTOPInside both PMBus CommandRead and PMBus CommandWrite functions,PMBus DataLengthCalc is called which calculates the data length based on thecommand code received.2.1.3Read and write operationPMBus master performs read/ write operations with the slave device. Depending on thecommand code, either PMBus CommandRead or PMBus CommandWrite is called. Insidethis function, the SMBus transaction type is selected as shown in the following sequence.Figure 4.Flowchart: read operationSTARTYesCheck if SMBus Mode forByte commandSMBus Read byte protocol1711811711811SSlave AddressWrACommand CodeASSlave AddressRdAData ByteAPNoCheck if SMBus Mode for WordcommandYesSMBus Read word protocol171181171181SSlave AddressWrACommand CodeASSlave AddressRdAData Byte LowA.NoYesCheck if SMBus Mode forSend Block commandNo811Data Byte HighAPSMBus Read block protocol171181171181SSlave AddressWrACommand CodeASrSlave AddressRdACount Byte 1A.STOP8181.811Data Byte 1AData Byte 2A.Data Byte NAPDoc ID 13286 Rev 29/43
Implementation of PMBus using ST7 I2CFigure 5.AN2511Flowchart: write operationSTARTYesCheck if SMBus Mode forSend Byte commandSMBus Send byte protocol1711811SSlave AddressWrAData ByteAPNoYesCheck if SMBus Mode for WriteByte commandCheck if SMBus Mode for WriteWord commandSMBus Write byte protocol171181811SSlave AddressWrACommand CodeAData ByteAPYesSMBus Write word protocol17118181811SSlave AddressWrACommand CodeAData Byte LowAData Byte HIghAPNoYesCheck if SMBus Mode forWrite Block commandNoSMBus Write block protocol17118181181SSlave AddressWrACommand CodeAByte Count NRdAData Byte 1A.STOP81.811Data Byte 2A.Data Byte NAPDuring the PMBus communication, if there are any errors in communication (acknowledgefailure, arbitration loss, bus error or SMBus timeout), the I2C peripheral is disabled. It is reinitialized again inside the PMBus write/ read functions.In case the SMBus Alert pin is pulled low by the slave to inform the master that it wants tocommunicate, the slave address is programmed with the alert response address (0x18).This is acknowledged by the slave that alerted the master. After the communication betweenthe master and slave is complete, the slave address is programmed with the user-definedslave address. The default value of this user-defined address is 0x30.In case of group operation, the write operation flowchart is followed without the stopcondition.10/43Doc ID 13286 Rev 2
AN2511PMBus commands and source code3PMBus commands and source code3.1PMBus commandsThe Part II - command language document of PMBus Power System ManagementProtocol Specification v1.0 provides the list of PMBus commands. This driver supports thefollowing list of commands. For each command a table is given.Table 1.OperationCommand nameOPERATIONCommand code01hDescriptionThe OPERATION command is used to turn theunit on and off in conjunction with the input fromthe CONTROL (OUTEN) pin.SMBus transaction typeRead/ Write byteNumber of data bytes1Table 2.ON OFF CONFIGCommand nameON OFF CONFIGCommand code02hDescriptionThe ON OFF CONFIG command configures thecombination of CONTROL (OUTEN) pin inputand serial bus commands needed to turn the uniton and off.SMBus transaction typeRead/ Write byteNumber of data bytes1Table 3.CLEAR FAULTSCommand nameCLEAR FAULTSCommand code03hDescriptionCLEAR FAULTS is used to clear any fault bitsthat have been set.SMBus transaction typeSend byteNumber of data bytes0Doc ID 13286 Rev 211/43
PMBus commands and source codeTable 4.RESTORE DEFAULT ALLCommand nameRESTORE DEFAULT ALLCommand code12hDescriptionThe RESTORE DEFAULT ALL commandinstructs the PMBus device to copy the entirecontents of the non-volatile default store memoryto the matching locations in the operatingmemory. Any items in default store that do nothave matching locations in the operating memoryare ignored.SMBus transaction typeSend byteNumber of data bytes0Table 5.STORE USER ALLCommand nameSTORE USER ALLCommand code15hDescriptionThe STORE USER ALL command instructs thePMBus device to copy the entire contents of theoperating memory to the matching locations inthe non-volatile user store memory. Any items inoperating memory that do not have matchinglocations in the user store are ignored.SMBus transaction typeSend byteNumber of data bytes0Table 6.12/43AN2511VOUT MODECommand nameVOUT MODECommand code20hDescriptionVOUT MODE command, used for commandingand reading output voltage, consists of a three bitmode (only linear format is supported.) and afive-bit parameter representing the exponentused in output voltage Read/Writes.SMBus transaction typeRead/ Write byteNumber of data bytes1Doc ID 13286 Rev 2
AN2511PMBus commands and source codeTable 7.VOUT COMMANDCommand nameVOUT COMMANDCommand code21hDescriptionVOUT COMMAND is used to set the outputvoltage, in volts (linear format).SMBus transaction typeRead/ Write wordNumber of data bytes2Table 8.VOUT MAXCommand nameVOUT MAXCommand code24hDescriptionThe VOUT MAX command sets an upper limiton the output voltage the unit can commandregardless of any other commands orcombinations.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 9.VOUT MARGIN HIGHCommand nameVOUT MARGIN HIGHCommand code25hDescriptionThis VOUT MARGIN HIGH command loads theunit with the voltage to which the output is to bechanged when the OPERATION command is setto "Margin High".SMBus transaction typeRead/ Write wordNumber of data bytes2Table 10.VOUT MARGIN LOWCommand nameVOUT MARGIN LOWCommand code26hDescriptionThis VOUT MARGIN LOW command loads theunit with the voltage to which the output is to bechanged when the OPERATION command is setto "Margin Low".SMBus transaction typeRead/ Write wordNumber of data bytes2Table 11.VOUT OV WARN LIMITCommand nameVOUT OV WARN LIMITCommand code42hDoc ID 13286 Rev 213/43
PMBus commands and source codeTable 11.VOUT OV WARN LIMIT (continued)DescriptionThe VOUT OV WARN LIMIT command sets thevalue of the output voltage at the sense or outputpins that causes an output voltage high warning.This value is typically less than the outputovervoltage threshold.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 12.VOUT UV WARN LIMITCommand nameVOUT UV WARN LIMITCommand code43hDescriptionThe VOUT UV WARN LIMIT command sets thevalue of the output voltage at the sense or outputpins that causes an output voltage low warning.This value is typically greater than the outputundervoltage fault thresholdSMBus transaction typeRead/ Write wordNumber of data bytes2Table 13.IOUT OC FAULT LIMITCommand nameIOUT OC FAULT LIMITCommand code46hDescriptionThe IOUT OC FAULT LIMIT command sets thevalue of the sense output current, in amps (literalformat), that causes an overcurrent fault.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 14.IOUT OC WARN LIMITCommand nameIOUT OC WARN LIMITCommand code4AhDescriptionThe IOUT OV WARN LIMIT command sets thevalue of the output current that causes an outputovercurrent warning.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 15.14/43AN2511OT FAULT LIMITCommand nameOT FAULT LIMITCommand code4FhDescriptionThe OT FAULT LIMIT command sets the valueof the sense temperature, in C (literal format),that causes an overtemperature faultDoc ID 13286 Rev 2
AN2511PMBus commands and source codeTable 15.OT FAULT LIMIT (continued)SMBus transaction typeRead/ Write wordNumber of data bytes2Table 16.OT FAULT RESPONSECommand nameOT FAULT RESPONSECommand code50hDescriptionThe OT FAULT RESPONSE command instructsthe device on what action to take in response toan overtemperature fault.SMBus transaction typeRead/ Write byteNumber of data bytes1Table 17.OT WARN LIMITCommand nameOT WARN LIMITCommand code51hDescriptionThe OT WARN LIMIT command sets the valueof the sense temperature, in C (literal format),that causes an overtemperature warning.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 18.TON DELAYCommand nameTON DELAYCommand code60hDescriptionThe TON DELAY sets the time, in ms, from whena start condition is received (CONTROL signalasserted and a valid OPERATION commandreceived) until the output voltage starts to rise.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 19.TON RISECommand nameTON RISECommand code61hDescriptionThe TON RISE sets the time, in ms, from whenthe output starts to rise until the voltage hasentered the regulation band.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 20.TOFF DELAYCommand nameTOFF DELAYCommand code64hDoc ID 13286 Rev 215/43
PMBus commands and source codeTable 20.TOFF DELAY (continued)DescriptionThe TOFF DELAY sets the time, in ms, fromwhen a stop condition is received (CONTROLsignal negated or a valid OPERATION commandreceived) until the unit stops transferring energyto the output.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 21.TOFF FALLCommand nameTOFF FALLCommand code65hDescriptionThe TOFF FALL sets the time, in ms, from theend of the turnoff delay time until the voltage iscommanded to zero. Note that this command canonly be used with a device whose output can sinkenough current to cause the output voltage todecrease at a controlled rate.SMBus transaction typeRead/ Write wordNumber of data bytes2Table 22.STATUS BYTECommand nameSTATUS BYTECommand code78
August 2010 Doc ID 13286 Rev 2 1/43 AN2511 Application note PMBusTM interface using ST7 I2C Introduction The PMBus TM (power management bus) is an open standard protocol that defines a means of communicating with power conversion and other devices. The PMBus protocol helps to
STM32CubeIDE quick start guide - User manual Author: STMICROELECTRONICS Subject: STM32CubeIDE is STMicroelectronics integrated development environment for STM32 microcontrollers and microprocessors. Keywords: STM32, IDE, Eclipse , QSG Created Date: 11/2/2020 4:57:17 PM
[2]. Ben Jordan, Amit Bahl Rigid - Flex PCB Design a guide book for design, Sierra Proto express, 2013 [3]. STMicroelectronics. STM32 embedded graphic objects/ touchscreen library, 2011. [4]. STMicroelectronics. STM32F10xxx ı2c optimized examples, 2010. [5]. STMicroelectronics. Migratin
How a designer can make the most of STMicroelectronics serial EEPROMs Introduction Electrically Erasable and PROgrammable Memory (EEPROM) devices are standard products used for the non-volatile storage of data parameters, with a fine-granularity. This application note describes most of the internal architecture and related functionality of
– Electrostatic discharge protection Application Reverse battery protection of an electronic control unit Description The VN5R003H-E is a device made using STMicroelectronics VIPower technology. It is intended for providing reverse battery protection to an electronic module. This devic
Application note SPC560Pxx/SPC56APxx HW design guideline Introduction This application note is intended for hardware designers. It gives hardware design references on SPC560Pxx/SPC56APxx microcontroller. Four topics are covered: Voltage Regulator (VREG) Main oscillator Supply pins Reference Reset circuit www.st.com
March 2017 DocID028650 Rev 3 1/7 For further information contact your local STMicroelectronics sales office www.
User manual Discovery kit with STM32L496AG MCU Introduction The 32L496GDISCOVERY Discovery kit is a complete demonstration and development platform for the STMicroelectronics Arm Cortex -M4 core-based STM32L496AGI6 microcontroller. Thanks to the innovative ultra-low-power-oriented features, extended RAM,
ASTM C167-15 – Standard Test Method for Thickness and Density of Blanket or . Batt Thermal Insulations. TEST RESULTS: The various insulations were tested to ASTM C518 and ASTM C167 with a summary of results available on Page 2 of this report. Prepared By Signed for and on behalf of. QAI Laboratories Ltd. Robert Giona Matt Lansdowne Senior Technologist Business Manager . Page 1 of 8 . THIS .
