| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To achieve a nonvolatile semiconductor memory device in which data requiring security can be stored like the identification number being intrinsic to a chip. <P>SOLUTION: Information indicating the number of times of erasure of the erasion unit region is present in the management information region of the erasure unit region in a part of region or a whole region of a memory region, and when the information is the prescribed value, voltage required for erasure is not applied to the word line or the data line or the source line of part of the region or the whole region, Also, the same control is performed for writing. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
