BQ27742-G1: Accessing Data Flash

PY (Pengyu) Song

Part Number: BQ27742-G1
Other Parts Discussed in Thread: BQSTUDIO, EV2400

Hi team,

Customer is having difficulty accessing the data flash.

Writing 0x00 to the BlockDataControl() (0x61) register always failed, which led to unseal the device first. Procedure for unsealing the device does not seem straightforward and even after writing the unseal key 0x8000 to the control command as mentioned in the spec, data flash access seemed to fail. CONTROL_STATUS always shows the device is in FULL ACCESS mode.

Do you have any examples to unseal the device and to read data flash block offset with success?

over 1 year ago

+1 Wyatt Keller over 1 year ago

TI__Guru** 102455 points

Hello PY,

I would suggest using an EV2400 for initial setup and debug, you will need it regardless to program the correct chem ID. With the EV2400 and BQStudio you can confirm if the gauge is unsealed and use a sniffer to see the unseal command sequence, you can also see the data flash access sequence. There are also some FAQs on how to unseal, it is with a different gauge but the procedure is very similar.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1122084/faq-bq34z100-g1-how-to-seal-and-unseal?tisearch=e2e-sitesearch&keymatch=faq%3Atrue

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ27742-G1: Accessing Data Flash