| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce an erasure time of a nonvolatile semiconductor memory. <P>SOLUTION: The nonvolatile semiconductor memory in the embodiment has a controller for determining whether data erasure to a plurality of memory cells in a memory cell array is conducted per block or per page. The controller includes: first means (ST1-ST2) for performing verification by a verification circuit after conducting block erasure (provisional erasure) under predetermined conditions; second means (ST3-ST4) for continuously conducting block erasure when the number of memory cells which is determined to be completely erased through verification by the verification circuit is equal to or less than n (n is a predetermined natural number); and third means (ST5-ST6) for continuously conducting the page erasure when the number of the memory cells which is determined to be completely erased through verification by the verification circuit is over n. <P>COPYRIGHT: (C)2012,JPO&INPIT |
