SLUUCW9 December 2023 BQ76972
The BQ76972 device integrates three serial communication interfaces–an I2C bus, which supports 100 kHz and 400 kHz modes with an optional CRC check, an SPI bus with an optional CRC check, which supports a clock rate up to 2 MHz, and a single-wire HDQ interface. The BQ76972 device is configured default in I2C mode (other versions of the device, such as the BQ7697201, can be configured in a different mode by default), and can be changed to SPI or HDQ mode by programming either the register or OTP configuration accordingly. The customer can program the device's integrated OTP on the manufacturing line to set the desired communications speed and protocol to be used at power up in operation.
The Settings:Configuration:Comm Type configuration register controls the active communication mode of the BQ76972 device. These settings are shown below.
Comm Type Setting | Description |
0x00 | Default ( I2C Fast on BQ76972, can be different for other versions of the device, per the device data sheet) |
0x03 | HDQ using the ALERT pin |
0x04 | HDQ using the HDQ pin |
0x07 | I2C (for use up to 100-kHz bus speed) |
0x08 | I2C Fast (for use above 100-kHz bus speed) |
0x09 | I2C Fast with timeouts (for use above 100-kHz bus speed) |
0x0F | SPI |
0x10 | SPI with CRC |
0x11 | I2C with CRC (for use up to 100-kHz bus speed) |
0x12 | I2C Fast with CRC (for use above 100-kHz bus speed) |
0x1E | I2C with timeouts (for use with 100-kHz bus speed) |
0xFF | I2C Fast (for use above 100-kHz bus speed) |
All other values | Reserved. Do not use. |