Abstract: A semiconductor storage device has a memory cell (501, 502) storing data; bit lines (BL1, BL2) connected to the memory cell, allowing therethrough data input or output to or from the memory cell; a sense amplifier (506a) connected to said bit lines, amplifying data on the bit lines; and a switching transistor (505a) connecting or disconnecting the bit line connected to the memory cell to or from the bit line connected to the sense amplifier. The switching transistor operates differently in a first memory cell access operation and in a second memory cell access operation.

Abstract: Regular data inputted/outputted to/from external terminals is read/written to/from a regular cell array, and parity data is read/written from/to a parity cell array. Since the parity data is generated by a parity generation circuit, it is difficult to write a desired pattern to the parity cell array. The regular data and the parity data are exchanged with each other by a switch circuit, so that the regular data can be written to the parity cell array and the parity data can be written to the regular cell array. This enables the write of desired data to the parity cell array. A test of the parity data can be easily conducted. In particular, a leakage test or the like between memory cells can be easily conducted.