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bq76940/bq76930/bq76920 Software
11 SLVU924D – March 2014 – Revised November 2018
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bq76920 Evaluation Module User's Guide
The Read Device button at the top of the Registers view provides important setup of the
bq76940/bq76930/bq76920 software and the IC. The software reads the factory gain and offset data from
the device and populates these in the
Stack V/T/I section for use in calculating display values. The
software writes the CC_CFG register to its proper value and also detects the CRC mode of the device and
sets the software appropriately.
The control registers are shown in the center of the display in the All Read/Write Registers section. Bits
are color coded as described in the section. Bits may be changed by clicking on the bit and selecting
Commit button in the Change value pop-up window. The default for the pop up window is to change the
polarity of the bit. Since clearing status bits requires a write of 1, the Set bit high needs to be checked in
the Change value pop-up window when clearing status register bits. A bit value change is displayed if the
Options menu Verify Writes is selected.
Control registers can also be changed as register values by writing in the value box to the right of the
value box. Scan must be disabled to enter values. Register values may also be changed using the I2C
byte write tool at the top of the window. Register changes are visible if the Verify Writes option is enabled.
The display may also be updated using the
Update Display button or selecting Scan .
The All Read/Write Registers section contains 4 buttons to the right of the register display:
• Update Display : This button reads all control and value registers and updates the values, bit breakout
fields and control features.
• Clear Faults : This button clears the status register.
• Save Configuration : This button allows saving the displayed values of the control register to a file. A
pop-up box allows selection of the file name. The default file location is C:\Users\<account-
name>\Documents\Texas Instruments\bq76940.
• Load configuration : This button allows loading the control register values from a file. A pop-up box
allows selection of the file, another pop up box lets you select whether to write the values to the
device. If faults are not set in the status register value in the file, they are not cleared by the write.
The Base Configuration section shown above the register detail provides convenient control of the
Coulomb Counter, ADC and Temperature Sensor selection as functional controls without locating the
control bits.
The Data Scanning section allows periodic read of the device and display of the register values. The Scan
check box enables the read when checked. The update interval is displayed and can be changed with the
Change Interval button.
The Logging section has the Start Logging button. The values read from the device can be saved to a
file. Selecting the Start Logging button opens a bq76940 Logging popup window to enter the file name,
comments and to select the data groups to be logged. The file name must be entered with the pop up
window's
Browse button. The scan interval can be changed, and the logging is actually started in the pop
up window. When logging is active, the registers user interface cannot be used and the button changes to
Stop Logging . Selecting the button stops the logging. Scan is not necessary before logging, it will start
with logging and cannot be disabled during logging.
The Stack V/T/I section is on the right side of the Registers view ( Figure 4 ). The ADC Gain and Offset
boxes show the values that are used for converting the register data into values. These value boxes are
read only, they are updated by the values read from the device with the
Read Device button. The Display
raw data read from device below check box allows display of the hex register values rather than converted
values. The V/T/I values are updated by the Read Device button, the Update Display button, or the Scan
option.
4.4.5 I2C Pro View
Figure 5 shows the I2C Pro view of the GUI. The I2C Pro view is useful to read or write several sequential
registers. If another view is displayed, it can be selected using the I2C PRO button on the left side of the
window or from the menu. The I2C Command box for each section specifies the starting register address
for the transaction.