TS-7840 RTC

This board includes an onboard battery backed ST M41T00S using an external and replaceable coin cell battery. The RTC is connected to the CPU via I2C and is handled by the kernel, and is presented as a standard RTC device in linux (/dev/rtc0).

The default Debian Linux image will by default pull time from the rtc on startup, and set it each time there is a synchronization with NTP. By default, no manual interaction is needed for the RTC to function, but if needed hwclock is typically used to interface with the RTC.

The RTC ships with an initial synchronization from the factory, but if the battery is shorted or removed during installation in the field it may lose its time.