BQ40Z50-R3-DEVICE-FW: Read Block: No acknowledge from device

Andy Coe

Part Number: BQ40Z50-R3-DEVICE-FW

I am trying to change the UNSEAL and FULL ACCESS keys using BQ studio. I am using the Advanced Comm SMB tab and trying to read and write block 35 hex but I get Read Block: No acknowledge from device I am able to read some of the other blocks. It seems pointless sealing the pack if the keys are left at the default. I have trawled the data sheet and looked for any other app notes that may point me in the correct direction but I have hit a void. Has anyone had any experience with this issue please?

over 4 years ago

0 Jayden Li over 4 years ago

TI__Expert 3275 points

Hi, Andy

Could you provide screen shot of your BQStudio? I would check if you have correct operation.

Actually, you need to input 44 in write block and 35 00 in block, then click write block. And input 44 in read block, then click read block. Then you would get the key you want.

Sincerely,

Jayden

0 Andy Coe over 4 years ago in reply to Jayden Li

Prodigy 90 points

Hi Jayden

Thank you for the reply.

As you can see I do get a value returned following your proscribed method.

I don't understand what the reply represents though as I would have expected a length of 16 rather than 6 for the security keys and the result doesn't seem to have a relationship to the defaults that I would have expected.

Regards

Andy

0 Andy Coe over 4 years ago in reply to Jayden Li

Prodigy 90 points

0 Jayden Li over 4 years ago in reply to Andy Coe

TI__Expert 3275 points

Hi Andy,

Have you fully unsealed your device before Block read/write? If not, please fully unsealed your device and do it again.

Sincerely,

Jayden

0 Andy Coe over 4 years ago in reply to Jayden Li

Prodigy 90 points

I believe that I am fully unsealed but I am not 100% sure. every read from 44 gives the same reply regardless of what I write to 44 previously.

0 Jayden Li over 4 years ago in reply to Andy Coe

TI__Expert 3275 points

Hi Andy,

Please try to input 00 in write word and 0035 in word, then click write word. And input 44 in read block, then click read block.

Sincerely,

Jayden

0 Andy Coe over 4 years ago in reply to Jayden Li

Prodigy 90 points

Hi Jayden

Unfortunately it still returns the same set of 6 values

Regards

Andy

0 Jayden Li over 4 years ago in reply to Andy Coe

TI__Expert 3275 points

Hi Andy,

I mean input 00 in Write Word and 0035 in Word, not input 44 in Write Block and 35 00 in Block. Then click write word. And input 44 in Read Block, then click Read Block.

Sincerely,

Jayden

0 Andy Coe over 4 years ago in reply to Jayden Li

Prodigy 90 points

Hi Jayden

Thanks for that I hadn't realised that information in the write block fields would have an effect even when not using the write block button.

I believe I now have the values of the keys, I just need to figure how to change them and seal the pack. Also how to unseal them with the new keys.

The documentation isn't very clear regarding how to use the advanced comms on BqStudio to perform these procedures, I think it assumes a familiarity with SM bus communications that I don't have and the BQ40 datasheet also just glosses over such issues.

Thanks again for your help.

Regards

Andy

0 Andy Coe over 4 years ago in reply to Andy Coe

Prodigy 90 points

Hi Jayden

If the unseal key is written as 01 23 45 67 what format do I enter the unseal key to unseal the device using the unseal command in BqStudio.

I used the above and it doesn't seem to work.

Regards

Andy

0 Jayden Li over 4 years ago in reply to Andy Coe

TI__Expert 3275 points

Hi Andy,

You can try 23016745.

Sincerely

Jayden

0 Andy Coe over 4 years ago in reply to Jayden Li

Prodigy 90 points

Hi Jayden

I found that 67452301 worked.

Regards

Andy

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BQ40Z50-R3-DEVICE-FW: Read Block: No acknowledge from device