| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device in which write can be performed and a lifetime can be lengthened. <P>SOLUTION: This device has a memory cell array having a plurality of blocks being writable and erasable, a control means having an erasing flag indicating whether each of a plurality of blocks is already erased or not, a control means detecting unused blocks out of a plurality of blocks and writing new data in the unused blocks, a means setting an erasing flag corresponding to a block in which old data to be rewritten is recorded to 'erased', an erasing means erasing selectively a block in which an erasing flag is set, a means corresponding a logic address corresponded to a physical address of a block having old data to a physical address of a block in which new data is written. Each of a plurality of blocks is an erasing unit as a unit being smaller than a nonvolatile semiconductor memory chip in which a memory cell array is realized. <P>COPYRIGHT: (C)2003,JPO</p> |
