MCU RTC - Geowissenschaften/EXCISS GitHub Wiki
DS3231MZ+ is a realtime clock. It utilises a coin cell to keeps the clock running without VSYS is powered.
Main purpose is, to have a correct time and date value for event logging and scheduled tasks. Also the RTC generates a clock signal for the MCU. The RTC is controlled via i2c by the MCU. Because the SCU doesn't have a power independent RTC, the SCU must acquire the current date and time from the MCU's RTC.
Vendor device website: https://www.maximintegrated.com/en/products/digital/real-time-clocks/DS3231M.html
Datasheet download link: https://datasheets.maximintegrated.com/en/ds/DS3231M.pdf