NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE AND WRITING CONTROL METHOD FOR NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE

PROBLEM TO BE SOLVED: To provide a non-volatile semiconductor storage device capable of achieving writing operation including rewriting of data and reading operation by input/output of addresses and data with the small number of clocks, and to provide a writing control method for the non-volatile semiconductor storage device.SOLUTION: The non-volatile semiconductor storage device includes first to forth memory areas 11 to 14 respectively having non-volatile memory cells. The first memory area 11 is selected in accordance with an inputted address. The third memory area 13 is selected by the same row address as the first memory area 11. The second memory area 12 is selected instead of the first memory area 11 in accordance with index data S read out from the third memory area 13. At the time, whether the second memory area 12 has been used or not is determined on the basis of a used flag F stored in the fourth memory area 14 selected in accordance with the same index data S in common with a row address of the second memory area 12. Thus, data rewriting operation and reading operation of rewritten data can be performed by minimum necessary reading operation.