| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory which can selectively erase data with reduced erasure stress and an electronic instrument using it. <P>SOLUTION: This nonvolatile semiconductor memory has; a cell array in which an electrically rewritable nonvolatile memory cell is arranged at each intersection of a plurality of word lines and bit lines crossing mutually; a row decoder which selects and drives a word line of the cell array; a sense amplifier circuit which reads and writes data of the cell array; and a controller which performs sequence control in writing and erasing data. In this nonvolatile semiconductor memory, in a data erase cycle where data erasure of a memory cell along with at least one selected word line of the cell array is performed under the control of the controller, an adjoining and non-selected word line which adjoins a selected word line, out of non-selected word lines in the cell array are precharged at a first erasure prohibiting voltage, and the remaining non-selected word lines are precharged at a second erasure prohibiting voltage different from the first erasure prohibiting voltage. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
