The data memory cell array and parity memory cell array in the memory cell array has a constitution that is capable of corresponding with a plurality of ECC code lengths. An input-side parity generation circuit that generates parities from write data, an output-side parity generation circuit that generates parities from read data, and a syndrome generation circuit that generates a syndrome bit that indicates an error bit from the read parity bits and generated parity bits are constituted so as to be capable of switching, according to the plurality of ECC code lengths.