In some applications, the host does not always monitor the charger operation. The INT pulse notifies the system on the device operation. The following events will generate 256-μs INT pulse.

• USB/adapter source identified (through PSEL pin )
• Good input source detected
  • VBUS above battery (not in sleep)
  • VBUS below V_{VAC_OV} threshold
  • VBUS above V_VBUSMin (typical 3.8 V) when I_BADSRC (typical 30 mA) current is applied (not a poor source)
• Input removed
• Charge complete
• Any FAULT event in REG09
• VINDPM / IINDPM event detected (maskable)

When a fault occurs, the charger device sends out INT and keeps the fault state in REG09 until the host reads the fault register. Before the host reads REG09 and all the faults are cleared, the charger device would not send any INT upon new faults. To read the current fault status, the host has to read REG09 two times consecutively. The first read reports the pre-existing fault register status and the second read reports the current fault register status.