BQ76952: BQ76952 won't enter CONFIG_UPDATE mode

Hi Richard,

BQStudio does many things behind the scenes to make evaluation easy, one of those is to enter and exit config update mode without telling you.  If you go to the Data Memory page to make changes, it will enter and exit config update as needed.  If you are in the Data Memory page, enter config update mode and make a change, BQStudio will exit config update mode so that when you go to the register view you don't see it..   If you stay in the register view and use the "SET_CFGUPDATE" and "EXIT_CFGUPDATE" commands with scan you should be able to see the bit change in Battery Status.  If  To enter and exit config update mode as desired when configuring the part you will likely need to use an MCU.  See the software development guide appnote https://www.ti.com/lit/pdf/sluaa11 for additional reference beyond the technical reference manual.

Do you have other parts which work as expected?  What is the hex value for Battery Status?

Ah - the information about BQ studio doing the enter/exit is helpful!

However, when I am at the register view, I cannot get the batter status bit to show CONFIG_UPDATE if I press the SET_CFGUPDATE command button.

Additionally, the FETs do not turn off, nor can I change the FET_ENABLE status to use the DSG/CHG  FET test commands. 

(I did have the FET_ENABLE bit in MFG_STATUS, but I cleared that. Then the FETs disable, and I stil can't use SET_CFGUPDATE or DSG_TEST commands).

Hi Richard,

Be sure the registers are read in the register view after clicking on the SET_CFGUPDATE command to see the status bit.  However since you don't see the FETs turn off it is not going to config update since that turns off FETs.

The condition for not entering config update is a sealed device, from 12.3 Table of Command-only Subcommands:

DSGTEST and FET_ENABLE are similar:

What is the battery status hex value?

You might cycle power or send the RESET command.  If you have sealed the part and don't remember the key you will likely need to replace the part.

Battery hex is 0x0180

This is the status right after power up before programming. CFG_UPDATE  and FET commands are disabled for some reason

I root caused this to be a BQstudio issue.

I have a BQ34z100 on the same i2c -- at a different address. 

I configure the BQ76952 by setting the i2c address in BQs to 10. 

However, I observe through an i2c  analyzer that a handful of commands still try and use AA as the address even though the rest of BQ is using 0x10 for the registers, data memory, etc.

I observed this to be:

-  the "COMMAND" buttons (CONFIG_*, RESET, etc)

- Middle phase of the "read/export stream" (starts on 0x10, then sends some commands with 0xAA)

I believe this is something to do with the auto-detect logic in BQ. Is there a way  to turn that feature off and force BQ to only look at the bq76952?

Hi Richard,

That is a good find, I did not recognize that you had another supported device on the bus. 

BQStudio has a Window>Preferences>All Global Settings>Alt I2C Device Address where you can enter alternate address, I don't know if you can turn off auto detect.  

You can turn off dashboard refresh which stops the auto refresh portion, not sure it will turn off device autodetect.  Click on the green banner in Dashboard to make it turn red. 

Hi Richard,

If you download the new "Test" version of BQStudio, 1.3.104, under Window>Preferences>All global settings you can disable Auto Detect at launch.  You might see if this solves the issue you encountered.

Hi -- I tried this option but it does not work properly. Even though auto detect is off, bqstudio still probes the device at address aa and tries to configure bq7652 at AA, reading the wrong registers into the UI.

Hi Richard,

Thanks for letting us know, I will pass this on to the developers.  The only suggestion I have at this time is to start BQStudio without the bus connected, select the monitor, be sure auto detect is off, the connect to the bus.