STMicroelectronics STEVAL-ISQ006V1 User manual

November 2010 Doc ID 15846 Rev 1 1/31
UM0718
User manual
User manual for the USB to PMBus bridge
demonstration board
Introduction
The power management bus (PMBus) is a variant of the system management bus (SMBus)
which is targeted at digital management of power supplies. Like the SMBus, it is a relatively
slow speed two-wire communications protocol based on I2C. The PMBus protocol helps to
establish the first truly open communications standard for the digital control of power
systems facilitating the programming, control, and real-time monitoring of compliant power
conversion products.
This document describes how to set up and use the USB to PMBus bridge board for PMBus
communication. The objective of this demonstration board is to show the features and
capabilities of the PMBus using the ST7 I2C peripheral, to support the standard PMBus
commands. This demonstration board has an ST72651AR6 microcontroller (MCU) which
has an I2C peripheral. This microcontroller acts as the PMBus master. The demonstration
board works with a PC GUI and controls one or more PMBus compatible slaves connected
on the shared bus. The main purpose of this board is to interface with any compatible
PMBus devices making use of the supported set of commands.
The firmware of this application performs the PMBus bus protocols mentioned in PMBus
power system management protocol specification v1.1. The firmware is in C language.
Figure 1 shows the block diagram of this demonstration board.
Figure 1. USB to PMBus bridge - block diagram
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Contents UM0718
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Contents
1 Getting started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1 Package contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2 Hardware setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.1 Configuring the hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2.2 LED status indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 Software setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3.1 PC GUI installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Quick start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.4.1 Hardware configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.4.2 Software configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2 How to connect the demonstration board with the GUI . . . . . . . . . . . 13
2.1 Connecting the PC GUI with the demonstration board . . . . . . . . . . . . . . 13
2.2 Identification of PMBus slaves and options configuration . . . . . . . . . . . . 15
2.2.1 Polling the connected slaves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.2 Enabling the slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3 Advanced PMBus GUI description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.1 Device selection window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.1.1 Device selection window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.1.2 Memory selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.1.3 Device control section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.1.4 Monitoring section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2 Device setup window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.3 Loop comp. window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.4 Fault management window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.5 Device information window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.6 Device status window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.7 Manual command window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.7.1 Single command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.7.2 Group command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.8 Advanced setup window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
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4 Hardware details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1 Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.2 BOM list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.3 Physical dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
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List of tables UM0718
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List of tables
Table 1. Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 2. Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 3. LED indication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 4. PMBus connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 5. BOM list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 6. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
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List of figures
Figure 1. USB to PMBus bridge - block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Packaged board image, STEVAL-ISQ006V1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 3. PMBus GUI installation step 1 – welcome window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 4. GUI installation step 2 – license agreement window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 5. PMBus GUI installation step 3 - customer information window . . . . . . . . . . . . . . . . . . . . . . 9
Figure 6. PMBus GUI installation step 4 - installation path window . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 7. PMBus GUI installation step 5 - setup status window . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 8. PMBus GUI installation step 6 - setup finish window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 9. PMBus connector configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 10. Launching the GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 11. Connecting the board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 12. GUI connected to board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 13. Error in connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 14. List of connected slaves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 15. Selection of connected slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 16. Error message returned from the slave device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 17. Slave not supporting alert feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 18. Memory section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 19. Control signal section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 20. Status section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 21. Monitoring section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 22. Device setup window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 23. Loop comp. window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 24. Fault management window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 25. Device status window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 26. Manual command window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 27. Error in case of no slave address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 28. Write operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 29. Time-out error message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 30. Advanced setup window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 31. Microcontroller and PMBus section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 32. Top layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 33. Bottom layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
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Getting started UM0718
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1 Getting started
1.1 Package contents
The USB to PMBus bridge package includes the following items:
●Packaged hardware board (mechanical size: 79 mm x 39 mm x 20 mm) with a USB
connector
●User friendly graphical user interface (GUI) to:
– identify the connected PMBus slaves (up to four)
– configure, control, and monitor the connected slaves
– write/read different PMBus commands
– poll the alert response
1.2 Hardware setup
Figure 2 shows an image of the demonstration board.
Figure 2. Packaged board image, STEVAL-ISQ006V1
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1.2.1 Configuring the hardware
The connectors must be configured correctly, as described in Ta bl e 1 .
The user must connect the USB port of the PC or notebook to connect the demonstration
board. The demonstration board should also be connected with the compatible slave
module using the PMBus connector pins.
Table 1. Connectors
Connector
name Description
USB
Connector USB type B connector to communicate with the PC GUI
J3
ICC connector pins to re-program the MCU if needed. The connection is shown in the following
diagram:
Note: This 6-pin connection is a customized ICC connector from the normal
connector. This modification is performed to achieve the low-form factor of
the board.
J8 (PMBus)
The following is the 10-pin PMBus interface connector description:
– Pin 1: Control signal 5
– Pin 2: Control signal 4
– Pin 3: Control signal 3
– Pin 4: Control signal 2
– Pin 5: VDD_OUT. Refers to slide switch position.
– Pin 6: Ground
– Pin 7: Control signal 1
– Pin 8: PMBus alert signal coming from the slave device.
– Pin 9: PMBus clock signal. This signal is always driven by the MCU in this demonstration board.
– Pin 10: PMBus data signal. This signal is bi-directional.
Note: The voltage on the control lines is either 5 V or 0 V depending on the
selection made through the GUI.
Table 2. Switches
Switch name Description
SW1(Reset) The reset switch restarts the application
J9(EG1313) The voltage on VDD_OUT can be varied (5 V/ 3.3 V/NC) by varying the slide
switch positions.
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1.2.2 LED status indication
This demonstration board has 2 LEDs. Their operations are described in Ta b l e 3 .
Note: The connector (J3), switch (SW1), and LEDs (D2 and D3) are visible only when the casing is
removed. For normal operation the user need not worry about these. These are needed only
when the board is used for debugging purpose.
1.3 Software setup
This section explains how to install and set up the PC GUI for PMBus communication.
1.3.1 PC GUI installation
To install the PC GUI software, follow the steps as mentioned below:
Step 1:
As soon as the user clicks the PC GUI setup icon, the following window appears. Please
click on the “Next” button.
Figure 3. PMBus GUI installation step 1 – welcome window
Table 3. LED indication
LED Description
D2 ON: PMBus communication is ongoing.
OFF: no PMBus communication.
D3 ON: board is powered and MCU is running
OFF: no power to board
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Step 2:
Read the license file and click the “Yes” button to accept.
Figure 4. GUI installation step 2 – license agreement window
Step 3:
Select one of the following options in Figure 5:
Figure 5. PMBus GUI installation step 3 - customer information window
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Step 4:
Please select the folder in which to install the software. By default it installs the software in
the following path: C:\Program Files\STMicroelectronics\.
Figure 6. PMBus GUI installation step 4 - installation path window
Step 5:
After selecting the folder and clicking the “Next” button, the software starts installing.
Figure 7. PMBus GUI installation step 5 - setup status window
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Step 6:
After installation is complete, the following window appears to indicate that the installation
has successfully completed.
Figure 8. PMBus GUI installation step 6 - setup finish window
After clicking the “Finish” button, the software has installed in the directory selected or in the
default directory. A shortcut of this software is also available in the START menu as well as
on the desktop.
1.4 Quick start
1.4.1 Hardware configuration
●Connect the demonstration board to the PC through a USB type B connector
●Select the supply voltage for the slave, using the EG1313 switch (5 V/3.3 V/ NC)
●Connect the PMBus slave, (See Figure 4 below).
Figure 9. PMBus connector configuration
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1.4.2 Software configuration
●Install the GUI provided with the package
●Open the GUI (by clicking on Start -> Programs -> STMicroelectronics -> Advanced
PMBus -> Advanced PMBus Software Application) or simply click on the shortcut of
Advanced PMBus Software Application available on the desktop
●Click on File -> Connect option or on Connect icon
●Press the polling button to identify the connected slaves
●The user can now control/monitor the desired slave by clicking on the slave address.
Table 4. PMBus connector
Pin Description
1 Control 5
2 Control 4
3 Control 3
4 Control 2
5 VDD_OUT
6 GND
7 Control 1
8 PMBus Alert
9 PMBus Clock
10 PMBus Data
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2 How to connect the demonstration board with the
GUI
The hardware and software must be set up as mentioned in Section 1.2 and Section 1.3.
Any PMBus compatible module that acts as the slave must be connected. Refer to the
relevant datasheets and development kit documents of the slave device.
Once the hardware board is connected to the PC, LED D3 lights up to indicate the MCU is in
USB powered state. If there is any problem in getting the LED to light up, press the reset
switch provided in the demonstration board. This switch restarts the application.
2.1 Connecting the PC GUI with the demonstration board
To connect the PC GUI with the demonstration board, the following steps, as mentioned
below, should be followed:
●Step 1: Click on Start -> Programs -> STMicroelectronics -> Advanced PMBus ->
Advanced PMBus Software Application, as shown below, or simply click on the shortcut
of Advanced PMBus Software Application available on the desktop
Figure 10. Launching the GUI
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●Step 2: Click on the File -> Connect option or click on the “Open Connection” button on
the tool bar
Figure 11. Connecting the board
If the demonstration board is connected to the PC GUI, it shows 'Connected' in the status
bar (on the bottom right-hand of the GUI screen) and the device selection window appears.
Figure 12. GUI connected to board
If there is any problem in the connection, the status bar shows 'Not connected' and the
following error message appears (Figure 13).
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Figure 13. Error in connection
2.2 Identification of PMBus slaves and options configuration
2.2.1 Polling the connected slaves
After connecting the interface board, the GUI should poll the bus to identify the connected
slaves.
In the polling procedure the GUI scans the entire slave address range except 0x18 which is
the alert response address. As soon as the polling completes, the GUI lists the connected
slave addresses in the device selection window. The GUI can support four simultaneous
PMBus slaves.
Figure 14. List of connected slaves
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As soon as the polling procedure completes, a slave must be selected, as shown in
Figure 15. The selected slave is highlighted in the device selection window and the
parameters corresponding to the selected slave are read from the slave device.
2.2.2 Enabling the slave
Figure 15. Selection of connected slave
If the user clicks on the parameters without selecting the slave, an error message appears
on the screen and it may cause undesired behavior.
Note: 1 Ensure that there is no faulty slave connected. If a faulty slave is selected through the GUI, it
may cause damage.
2 After polling, the connected slaves appear below the address block. Then, select the slave
address and start PMBus operation. Otherwise the GUI displays an error message.
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Figure 16. Error message returned from the slave device
After selecting the slave, the bus setting and memory buttons are available. Now, any of the
windows can be selected to configure the PMBus slave device.
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3 Advanced PMBus GUI description
The PMBus GUI consists of 8 different windows where the device selection is the parent
window:
1. Device selection window
2. Device setup window
3. Loop comp. window
4. Fault management window
5. Device information window
6. Device status window
7. Manual command window
8. Advanced setup window
3.1 Device selection window
The device selection window is the parent window of the GUI and opens automatically as
soon as the demonstration board is connected, irrespective of whether the slave is
connected or not. This window has the following options:
1. Device selection
2. Memory
3. Device control
4. Device monitoring
3.1.1 Device selection window
As soon as the demonstration board is connected, the user must perform polling to identify
the connected PMBus slave devices. After polling the bus, the GUI shows the list of
connected slaves which can be selected, one at a time, for configuration or monitoring. As
soon as the slave is selected, and the bus setting window is clicked, the CAPABILITY
command is sent. The CAPABILITY command reads the supported features of the slave
device.
Based on the data received from the slave, the buttons on the GUI are enabled or disabled.
For example, if the slave does not support the PEC, the PEC enable button is disabled.
Similarly, the alert and 400 kHz buttons are disabled if not supported by the slave.
Figure 17. Slave not supporting alert feature
Once PEC is enabled, this interface board communicates the PEC value after the last byte,
in case it is a transmitter. The receiver returns a NACK for the PEC value, if the PEC value of
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the transmitter is different to that of the receiver. In this case, the GUI displays the error
message ‘PEC failure’. In the case of the receiver, the PEC value is received after the last
byte by this board and compared with a calculated PEC value. The GUI displays the error
message ‘PEC failure’, if the PEC value of the transmitter is different to the calculated value.
The speed of the PMBus communication can be configured by checking the corresponding
box against 100 kHz or 400 kHz.
3.1.2 Memory selection
This section has two buttons to move the PMBus related data from operating memory to
non-volatile memory or vice-versa. At the conceptual level, the PMBus slave operates from
the values stored in the volatile memory while a non-volatile memory (if supported by the
PMBus slave) is called default store. The restore button instructs the PMBus slave device to
copy the entire contents of the non-volatile user store memory to the matching locations in
the operating memory. The values of the operating memory are overwritten by the values
read from the non-volatile memory. Any item in the user store, not having a matching
location in the operating memory, is simply ignored.
Note: The user must confirm the behavior of store and restore commands with the manufacturer.
Sometimes, use of the above commands while the device is operating, may lead to
undesirable or damaging behavior.
Figure 18. Memory section
3.1.3 Device control section
This section can be subdivided into four blocks:
1. Operation
2. Control signal
3. ON/OFF configuration
4. Status
As soon as the PMBus slave is selected, all the parameters are read automatically from the
device. They can then be modified by the user. In the control signal section, the checked box
indicates the signal value to turn ON the selected slave. This may be low (if the slave is
active low enabled) or high (if the slave is active high enabled). The user can switch off the
device by reversing this signal. It must be switched on with the correct control signal value
(high or low) to restart the operation.
Figure 19. Control signal section
The status section indicates the PMBus status of the selected slave and can be periodically
monitored by putting the update interval value. When the clear faults button is pressed, all
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the faults are cleared and the GUI updates the values of the flags by reading the status. If
there is still a fault present, shown in the GUI, the user must resolve the problem.
Figure 20. Status section
3.1.4 Monitoring section
In this section the current and voltage related parameters are read at the time of slave
selection and can be periodically updated by changing the update interval value.
Figure 21. Monitoring section
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