| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory apparatus in which a defective cell can be replaced automatically by a redundant cell in the apparatus itself even if a defective cell is generated in a market. <P>SOLUTION: A memory cell array has a main body cell array 11 having a plurality of memory cells and a redundancy array 12 having a plurality of redundant cells being replaceable by a memory cell. An erasing circuit 22 performs erasing operation for object cells including either of a memory cell or a redundant cell, and an elapse time from start of erasing operation for the object cell is measured by a timer 14. When a control circuit 13 recognizes that the prescribed time elapses from start of erasing operation by measuring the elapse time by the timer 14, the control circuit 13 stops erasing operation and the object cell is replaced by the redundant cell. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
