| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make it possible to efficienlyt execute a tip batch erasing operation even if a defective memory cell exists in a nonvolatile semiconductor memory. <P>SOLUTION: This memory is provided with a memory cell array 9 having a plurality of blocks 10<SB>-i</SB>composed of a plurality of memory cells, a set means 3 for setting the execution allowed time of the erase operation per one block, and an erase means 2 capable of batch erasing storage data stored in the memory cell, for every block. By this arrangement, in the case the stored data in all memory cells of the memory cell array 9 are successively erased for every block, when the erase of the stored data in the memory cell constituting the block is not completed within the set execution allowed time, the erase operation at the block is forcibly finished so that the erase operation in the next block can be started. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
