BQ28Z610-R1: Impossible to change seal key

Hello Charles,

1. Make sure that the gauge is unsealed

2. Ensure that the voltage of the battery is greater than "Valid update voltage" that is present in data flash

3. Wait at least 250ms after writing the checksum

Hello Shirish,

1. The gauge is unsealed. And I tested on a board that was never sealed.

2. "Valid update voltage" = 2800mV. Circuit Voltage = 3700mV

3. It's ok. There is 1min between the checksum and the reading register. However, Is there a maximum delay between the write command and the checksum?

Hello Charles,

With long intervals between commands, it is possible that bqStudio sends other commands in between, This will result in break in sequence of commands. Try by turning off Registers scanning and turning Dashboard refresh off. 

Just to clarify: gauge must be in full access mode. This is the default for a board that was never sealed, so your board is in full access mode already.

Hello Shirish,

I used a sniffer / frame analysis.

You can view the results in attached file.Read-security-register.xlsx

legend: 

• Orange: cmd to read security register 
• Yellow: reading (default codes)
• Bright green: cmd to write new seal code
• Green: checksum

There are no parasitic patterns. And the BQStudio is correctly configured according to me.

Unfortunately, the modification of seal key is not a sucess...

My apologize, 

here the correct file: Read-security-register - 2.xlsx

(write checksum in 0x60 instead of 0x3e)

Hello Charles,

The procedure looks correct. Can you verify that you can update parameters in data flash using the data memory tab?

I'm not sure to understand. 

Following my comprehension, seal key and full access key are not written in the dataflash. Not like the BQ34z100 for example.
However, here the extract extract-DF.gg.csv

Hello Charles,

Flash writes are disabled under certain conditions. Under such conditions the seal key will also not be written. To rule this condition out, wanted to verify if other data flash areas are writable.

Hello Shirish, 

I read your previous message too quickly. Sorry.
I can change the dataflash (I tried with a security setting).

Hello Charles,

Have you been able to change the keys after verifying this?

Sincerely,

Wyatt Keller

Hello Wyatt, 

No, still not. I can modify the database with memory tab for other parameters. But the commands to modify "0x0035 Security Keys" doesn't work...

It should be read in my previous comment: I can change the dataflash (I tried with a PROTECTION setting)

Hello Charles,

Can you try using version 1.3.86.6? Here is a link:

https://www.ti.com/tool/download/BQSTUDIO-STABLE/1.3.86.6

The only reason I suspect this could be the issue is this thread:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1010769/bq28z610-r1-we-cannot-change-seal-key-when-using-bqstudio-1-3-101-or-1-3-102

But it seems to be a bit inconclusive.

Please let me know if this is indeed the case and we can figure out why.

Thanks,

Alex M.

Hello Alex, 

I tried with 1.3.86.6, but I obtained the same result.
I seen this topic. Unlike this example, I do not control by sending the unseal command but by reading of the 0x0035 register.

Note: Our circuits are in full access mode. 

Hello Charles,

I will try with an EVM and check if i can reproduce.

Hello Shirish, 

Thank you for your support. 
Indeed, my mistake was the reversal of bits for the length... I’m sorry I asked for this.

For information, I was able to change the security codes with version: 1.3.111

Best regards

Hello Charles,

Good to know that your issue is resolved! Thanks.