The 12-ms time-out from the PRE_RAMP state to the RAMP state starts only when all conditions for going to the RAMP state are satisfied. As soon as one of these conditions is violated, the 12-ms time-out is reset.
The oscillator is turned off in low-power mode. The oscillator is turned back on upon detecting a negative edge on the PS pin, or a negative edge on the PG pin which requires the device to go out of low-power mode and enter normal mode again.