RTC – Real Time Counter

Quick Facts

What?

The RTC is available in Energy Mode 0 to Energy Mode 2 and ensures timekeeping in low energy modes. Combined with the low power 32 kHz oscillator (XTAL or RC), the RTC can run in EM2 with current consumption less than 0.6 µA.

Why?

In many applications timekeeping over long time periods is required, while using as little power as possible.

How?

32 kHz oscillators are used as clock signal and the RTC has two different compare registers that can trigger a wake-up. 24-bit resolution and selectable prescaling allow the RTC to schedule infrequent and long periods before a wake-up is triggered. The system can then remain in EM2 for long a time and still maintain reliable timekeeping.