In some applications, the host does not always monitor charger operation. The INT pin notifies the system host on the device operation. By default, the following events generate an active-low, 256µs INT pulse.

1. Detection of a good input source
   • V_VIN < V_{VIN_OVP} threshold
   • V_VIN > V_{VIN_OK} threshold
2. Removal of a good input source
3. Entering IINDPM regulation
4. Entering VINDPM regulation
5. Entering IC junction temperature regulation (TREG)
6. Expiration of a I²C Watchdog timer
   • At initial power up, INT asserts to signal that I²C is ready for communication
7. Charger status changes state (CHARGE_STAT value change), including Charge Complete
8. TS_STAT changes state (TS_STAT any bit change)
9. Detection of VIN over-voltage (VIN_OVP)
10. Junction temperature shutdown (TSHUT)
11. Detection of battery over-voltage (BATOVP)
12. Expiration of charge safety timer, including trickle charge and pre-charge and fast charge safety timer expired
13. A rising edge on any of the other *_STAT bits

Mask off each one of the INT sources to prevent sending out INT pulses when the pulses occur. Three bits exist for each one of the pulse events:

• The STAT bit holds the current status of each INT source.
• The FLAG bit holds information on which source produced an INT, regardless of the current status.
• The MASK bit is used to prevent the device from sending out INT for each particular event.

When one of the above conditions occurs (a rising edge on any of the *_STAT bits), the device sends out an INT pulse and keeps track of which source generates the INT through the FLAG registers. The FLAG register bits automatically reset to zero after being read by the host, and a new edge on STAT bit is required to re-assert the FLAG. This sequence is illustrated in Figure 6-11.

Figure 6-11 INT Generation Behavior Example