| 摘要 |
<p>PURPOSE:To increase the life of a nonvolatile semiconductor storage even in such a use where the writing operations are concentrically carried out to a specific memory cell only. CONSTITUTION:The bit array of an address signal A is changed by a mapping changing part 12 before the address signals A0, A1 and A2 are supplied to a decoder part 10. The part 12 includes a selector 14 which selects and outputs an address in response to the output signal of an address mapping changing memory cell 16. Therefore, the address mapping can be changed when the value stored in the cell 16 is inverted in each prescribed period. Thus it is possible to prevent such a case where the writing operations are concentrically carried out to a specific memory cell only and then to increase the lives of the memory cell and a nonvolatile semiconductor storage.</p> |
