Fail-safe mode is a low power mode that different faults can cause the device to enter. Once in this mode, the SWE timer starts, if enabled. This provides a window of time to clear the faults and receive a wake event. If the faults are not cleared or a wake event doesn't take place prior to t_INACTIVE the device enters sleep mode to reduce power consumption. The fault must be cleared before a wake event is recognized for the device to enter the correct operating mode. This mode is default on and can be disabled by setting register 8'h17[0] = 1b. A fail-safe mode counter is available that after a set number of events in a row the device performs the programmed action which can include going to sleep and a WUP or LWU event does not wake the device. A power on reset is required. The counter is default disabled and can be enabled at 8'h17[7]. The counter expiration action is at 8'h17[6:4]. The number of events before action is programmed is set at 8'h18[7:4] with a value up to 15 events. 8'h18[3:0] is the running up/down fail-safe event counter that can be read and cleared.

If fail-safe mode is entered a global interrupt is issued, 8'h53[5] and the reason for entering fail-safe mode is provided by register 8'h17[3:1].