11.1.1.2.1 SOSC Start-Up Timing

The SOSC utilizes the Oscillator Start-up Timer (OST) to ensure that the 32.768 kHz crystal oscillator has started and is available for use. Crystal oscillators do not start immediately and may take a few hundred cycles before achieving stable operation. The oscillations must build up until sufficient amplitude is generated to properly toggle between logic states. The OST counts 1024 oscillation periods from the SOSCI input following a Power-on Reset (POR), Brown-out Reset (BOR), or wake-up from Sleep event to ensure that the oscillator has enough time to reach stable and accurate operation. Once the OST completes its count, module hardware sets the Secondary Oscillator Ready (SOR) bit, indicating that the SOSC is stable and ready to use.