A microcontroller includes a processor, a memory, a working space management unit and a memory monitor. The memory has at least a working space, wherein the working space includes a plurality of blocks . The working space management unit is implemented by software, and is arranged for managing the working space of the first memory. The memory monitor is implemented by hardware circuit, and is arranged for monitoring the blocks, and recording monitoring results corresponding to the blocks of the first memory, wherein the recorded monitoring results comprise information about whether data of the blocks is modified or not.