A low-cost tamper-resistant product package is provided. Two blocks of memory each have a different logical location with respect to a processor of the microcontroller. The ratio DaDo of the diameter Da of the supplementary coil to the diameter Do of the outer coil lies between 0,7 and 0,9. The first memory layer stack has a first conductive layer overlies a first programmable resistance random access memory layer. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.