SLUSDQ4 April 2019 BQ79606A-Q1
The oscillators used in the BQ79606A-Q1 are monitored by watchdog circuits. There are two oscillators in the device, the HFO and the LFO. If these oscillators are not functioning, the IC does not operate. If the HFO does not transition within tHFOWD or the LFO does not transition within tLFOWD, the watchdog circuits causes Digital Reset. It is recommended that the user sends a hardware shutdown command (using WAKEUP pin for a base device, or using the CONTROL1[SEND_SHUTDOWN] command for stack devices from the next lower device). Then the user must follow the WAKEUP procedure to restart the devices. If the oscillators are truly damaged, the device will not restart and must be replaced.
In addition to the watchdog, the LFO frequency is monitored to ensure it stays within acceptable limits. If the LFO frequency falls outside of the fLFO_CHECK specification, the SYS_FAULT3[LFO] bit is set.