SLUUCO5A december 2022 – august 2023 BQ34Z100-R2
When the device's SHA-1/HMAC internal engine is used, authentication keys are stored as plain-text in memory. A plain-text authentication key can only be written to the device while the IC is in UNSEALED mode. Once the IC is UNSEALED, a 0x00 is written to BlockDataControl() to enable the authentication data commands. Next, subclass ID and offset are specified by writing 0x70 and 0x00 to DataFlashClass() and DataFlashBlock(), respectively. The device is now prepared to receive the 16-byte plain-text key, which must begin at command location 0x4C. The key is accepted once a successful checksum has been written to BlockDataChecksum() for the entire 32-byte block (0x40 through 0x5F), not just the 16-byte key.