| 摘要 |
<p>PROBLEM TO BE SOLVED: To shorten a read-out time of data even if a first page is read-out many times. SOLUTION: This device is a multi-level memory having data of a state '0', a state '1', a state '2', and a state '3' in order of low threshold voltage, a memory cell in which data is a state '0' in write-in operation of a first page is made a state '1', a memory cell in which data is a state '0' in write-in operation of a second page is made a state '3', and a memory cell in which data is a state '1' is made a state '2'. Therefore, data of the first page can be read out by two times a the time of read-out of data. Further, as high initial write-in voltage can be used for write-in operation of the second page, write-in operation speed can be increased.</p> |
