BQ76952: Setting Serial number / Manufacture Date etc.

Klaus

Part Number: BQ76952
Other Parts Discussed in Thread: BQ40Z80

Hi Ti Experts,

we want to use the bq76952 in standalone mode for a 16S6P (21,6Ah) LiFePo application.

So far we have designed and produced a first PCB version.

Is there a possibility to set a Serial Number and a Manufacture Date in the bq76952.
We want to use it to have a traceability while and after production.

For example with the bq40z80 there is the possibility:

Thanks for helping us.

Klaus

over 4 years ago

0 WM5295 over 4 years ago

TI__Guru 54715 points

Hi Klaus,

The BQ76952 has the MANU_DATA sub command to write a 32 byte field in the OTP. Please see the 0x0070 MANU_DATA() Subcommand section in the data sheet. The data is stored in the OTP memory when written, but is not presently displayed in the Data Memory pages.

0 Klaus over 4 years ago in reply to WM5295

Expert 1327 points

Hi WM5295,

Thanks for your answer.

That is what I am looking for.

I have made two *.fs-Files.

first file:

2nd file:

It seemed to work well so far, but I do not understand how the checksum-calculation works.
In my example I have used "try and error" till I get the 0x90.

Could you make a example withe the numbers 0x70 0x00 0xFF?
How will this get to 0x90.

Thanks for helping us.

Klaus

0 Matt Sunna over 4 years ago in reply to Klaus

TI__Guru* 80843 points

Hi Klaus,

This app note might be helpful since it has a couple example cases where the checksum is calculated (see Page 10):

https://www.ti.com/lit/an/sluaa11/sluaa11.pdf

The checksum is the complement of the sum of the bytes after the 0x3E. For this case, you are writing (W: 10 3E 70 00 FF).

0x70 + 0x00 + 0xFF = 0x16F. The complement of the last 8 bits is 0x90 (flip all the bits in 0x6F).

I hope this helps,

Matt

0 Klaus over 4 years ago in reply to Matt Sunna

Expert 1327 points

Hi Matt,

thanks for your answer.

I think it was too late yesterday, sorry. Now it works almost.

If I use this *.fs-File it works:

If I add one Byte more like this,

it does not work.

I have tried to include delays (e.g. X: 500) at several places, but without to succeed.

If I understand the datasheet right, it should be possible to write 32 Bytes, isn't it?

Do you have a idea, what am I doing wrong?

Thanks a lot.

Klaus

0 Matt Sunna over 4 years ago in reply to Klaus

TI__Guru* 80843 points

Hi Klaus,

I am able to reproduce this behavior. I am investigating now with the firmware team to see what could be the problem.

I will let you know what I find,

Matt

0 Matt Sunna over 4 years ago in reply to Matt Sunna

TI__Guru* 80843 points

Hi Klaus,

I found the problem. The checksums are correct, but the length is the problem. It must be written in hex. The length '25' is actually decimal value 37 which is beyond the maximum value of 36.

I am attaching the .fs file I created with the lengths corrected and now it works.

Best regards,

Matt

/cfs-file/__key/communityserver-discussions-components-files/196/ManufacturingDataExamples.fs

0 Klaus over 4 years ago in reply to Matt Sunna

Expert 1327 points

Hi Matt,

thanks for for your answer.

I think now I am able to write the whole 32 byte field.

Thanks a lot.

Klaus

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BQ76952: Setting Serial number / Manufacture Date etc.