15.7 RTC Tamper Detect

The RTC provides several selectable polarity external inputs (INn) that can be used for tamper detection. When detect, tamper inputs support the four actions:

  • Off

  • Wake

  • Capture

  • Active layer protection

Note: The Active Layer Protection is a means of detecting broken traces on the PCB provided by RTC. In this mode an RTC output signal is routed over critical components onthe board and fed back to one of the RTC inputs. The input and output signals are compared and a tamper condition is detected when they do not match.
Separate debouncers are embedded for each external input. The detection time depends on whether the debouncer operates synchronously or asynchronously, and whether majority detection is enabled or not. Details refer to the section "Tamper Detection" of datasheet.