A device having a power supply monitoring capabilities, the device includes: a power supply unit; at least one real time clock generator counter adapted to receive a supply voltage from the power supply unit; a fixed value storage circuit that is un-accessible to software executed by a processor; wherein the fixed value storage circuit stores a fixed value; wherein the fixed value includes multiple bits; a volatile storage unit, being accessible to the processor; wherein the volatile storage unit is adapted to: (i) store a reset value after being reset; (ii) receive the fixed value during an initialization state; and (iii) store the fixed value until being reset; wherein the volatile storage unit is designed such that there is a low probability that the reset value equals the fixed value; and a comparator adapted to provide a tamper indication if the fixed value stored at the fixed value storage circuit differs from a value stored at the volatile storage unit.