| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device capable of realizing a security function without newly providing an operation mode and with a minimal additional circuit and its secret protection method. <P>SOLUTION: The security function is realized by using a column latch circuit 29 which performs batch write-in operations (a page latch operation, a page programming operation, a verification operation) preliminarily provided in the nonvolatile semiconductor storage device. A password for releasing the security function is stored in the column latch circuit 29 and the verification operation between the password stored in the column latch circuit 29 and a security release code stored in a release code storage section 13 is performed by control of a security control circuit 41. When the password is judged to coincide with the security release code by the verification operation, the security function is released. <P>COPYRIGHT: (C)2004,JPO</p> |
