A computing device can include a comparator coupled to an I/O pin of the computing device; a storage unit coupled to the comparator; and a counter coupled to receive an output of the comparator, an output of the counter being coupled to a computation engine to provide a limit-exceeded signal to the computation engine, wherein the counter comprises a volatile counter and a nonvolatile storage, wherein the nonvolatile storage stores a bit for each top volatile count number of events identified by the volatile counter. The computing device can further include a backup power source coupled to the volatile counter; and readout circuitry and control logic coupled to the volatile counter and to the nonvolatile storage, the readout circuitry and control logic being configured to control operations of the volatile counter during an error event and determine a total number of events. The computing device can be a smart card.