The active layer protection feature of the RTC can be tested as mentioned
below. The main function of Active layer protection is detecting the broken traces on
the PCB.
- Active layer protection involves two
pins called RTC/IN[n] and RTC/OUT for detecting tamper condition
- Connect one end of the PCB to the
RTC/IN [n] pin and the other end (which has continuity with IN[n] pin) to the
RTC/OUT pin
- Then define a known pattern of
waveform to the RTC/IN[n] pin and generate the same pattern at the RTC/OUT pin and
send it across the PCB routing
- If there are any broken traces in the
PCB or someone is attempting to remove the PCB, this will cause a mismatch in the
wave pattern at IN and OUT pins, which will trigger a tamper interrupt