A memory controller carries out error detection on a wide range of area of a memory cell array, which includes not only readout addresses but also non-readout addresses. Thus, by carrying out error detection at an address at which an error occurs without accessing the address for readout, it is possible to detect occurrence of an error at the address. Accordingly, it is possible to prevent a “read disturb phenomenon” in which repetition of access to a readout address for readout may probably cause an error at a non-readout address other than the readout address.