Part Number: BQ25188
The BQ2518x resets its R/W registers to the default values whenever a reset condition occurs. This can happen due to watchdog timers, power-on reset (POR), or a software-initiated reset.
Watchdog timer
The BQ2518x includes a watchdog timer that resets the R/W registers to their default values if an I2C transaction does not occur before the timer expires. The purpose of this watchdog is to return the device to a known state if the MCU becomes unresponsive.
The watchdog timer starts after the first I2C transaction to the device. The default watchdog timeout is 160s and is controlled by the WATCHDOG_SEL[1:0] bits in REG0x07. The watchdog timer can be disabled by setting these bits to 2b11.
After the watchdog timer expires, it resets after the next I2C transaction to the device.
15-second post-adapter watchdog
There is another watchdog timer that triggers a hardware reset if no I2C transaction occurs within 15s after a valid adapter is detected on VIN. During this hardware reset, the R/W registers are reset to their default values.
The 15s watchdog timer is controlled by the WATCHDOG_15S_ENABLE bit in REG0x0A.
Power-on reset (POR)
A power-on reset occurs whenever the device transitions from an unpowered state to a powered state. A POR resets all R/W registers to their default values.
Software reset
The REG_RST bit provides a software-initiated reset. When this bit is set, the R/W registers are reset to their default values.