SLUUCW9 December 2023 BQ76972
The BQ76972 device integrates an internal watchdog circuit for the internal processor, which triggers a watchdog fault if it is not serviced by the processor at regular intervals. A watchdog fault may occur if the internal processor is unexpectedly halted or overloaded with tasks, such as servicing excessive serial communications. When a watchdog fault occurs, the internal processor is reset, and the 0x12 Battery Status()[WD] bit is set after the reset is complete.
There are additional checks performed by the device which can also trigger a watchdog reset. The BQ76972 device incorporates an ADC measurement watchdog, which monitors whether the ADC and coulomb counter measurements are completing as expected, and if not triggers a watchdog fault. A RAM integrity check is also performed periodically and forces a watchdog reset if corruption is detected. If the device detects a RAM error within a programmable time (set by Power:Shutdown:RAM Fail Shutdown Time) after a watchdog reset, the device enters SHUTDOWN mode instead of resetting, to avoid unwanted reset loops in the case of a RAM failure.