When the input write data is a value of a value greater than the existing data of the memory array 100, the semiconductor memory device enables writing of input write data to the memory array 100. In specific terms, the increment controller 150 reads the existing data from the memory array 100, and compares it with the write data latched to the 8-bit latch register 170. When the value of the write data is a value greater than the existing data, the increment controller 150 outputs the write enable signal WEN1 to the write/read controller 140, and executes writing of the write data latched to the 8-bit latch register 170 to the memory array 100.