SLUAA11B February   2020  – August 2021 BQ769142 , BQ76922 , BQ76942 , BQ76952

 

  1.   Trademarks
  2. 1Direct Commands
    1. 1.1 Alarm Enable - 0x66
    2. 1.2 Cell 1 Voltage - 0x14
    3. 1.3 Internal Temperature - 0x68
    4. 1.4 CC2 Current - 0x3A
  3. 2Subcommands
    1. 2.1 DEVICE_NUMBER - 0x0001
    2. 2.2 MANUFACTURING STATUS - 0x0057
    3. 2.3 FET_ENABLE - 0x0022
    4. 2.4 RESET - 0x0012
  4. 3Reading and Writing RAM Registers
    1. 3.1 Read 'Enabled Protections A'
    2. 3.2 Enter CONFIG_UPDATE Mode
    3. 3.3 Write 'Enabled Protections A'
    4. 3.4 Write 'VCell Mode'
    5. 3.5 Exit CONFIG_UPDATE Mode
  5. 4I2C With CRC
  6. 5SPI With CRC Examples
    1. 5.1 Direct Command Example: Alarm Enable - 0x66
    2. 5.2 Direct Command Example: Cell 1 Voltage - 0x14
    3. 5.3 Subcommand Example: Device Number - 0x0001
    4. 5.4 Subcommand Example: FET_ENABLE - 0x0022
    5. 5.5 Subcommand Example: RESET - 0x0012
    6. 5.6 RAM Register Read Example: Enabled Protections A
    7. 5.7 RAM Register Write Example: Enabled Protections A
  7. 6Simple Code Examples
  8. 7References
  9. 8Revision History

3 Reading and Writing RAM Registers

A full view of registers in RAM can be found in the device-specific Technical Reference Manual and also in the Data Memory screen of BQStudio. To enable viewing the RAM register addresses in BQStudio, go to the Window->Preferences menu and select 'Show Advanced Views'. Reading from a RAM register is accomplished by writing the register address to 0x3E and then reading from the data buffer starting at 0x40. Writing to a RAM register starts with writing the register address to 0x3E followed by the data, followed by a write to 0x60/0x61 with the checksum and length. The checksum and length calculation is described more in the device-specific data sheet, but is illustrated in the following examples.

Note: When writing to RAM registers, it is highly recommended to first enter CONFIG_UPDATE mode and then perform the command to exit CONFIG_UPDATE mode once complete. This ensures stable operation while settings are being modified.