NONVOLATILE SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor device capable of testing memory cells in a region where key codes are stored without causing the key codes to be read.SOLUTION: A nonvolatile semiconductor device 10 includes: a key code storage block 13 that includes a key code storage region 14 where key codes are stored; and an indicator bit storage region 15 that stores data indicating whether or not access to the key code storage block 13 is granted. The rewriting of the indicator bit storage region 15 which is granted access to the key code storage block 13 is performed by erasing the data in the indicator bit storage region 15. When the data in the indicator bit storage region 15 is erased, the key codes are also erased.