| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problem wherein since read properties of memory cells of a nonvolatile semiconductor memory device are varied by the number of times of rewriting, under the fixed read condition, as the number of times of rewriting increases, reduction in reading speed and misreading are caused, and a highly accurate load resistor is required for reading data. <P>SOLUTION: In a write control circuit 113, after memory cells in a unit region, selected from a main array 100 and a monitor bit region 101 corresponding to the unit region, are erased when writing data, data are written in the unit region selected from the main array 100 and data determined in accordance with the number of times of rewriting of the unit region is written in the monitor bit region 101. In a read control circuit 114, when the data read from the monitor bit region 101 does not agree with predetermined data, the output voltage of a voltage source 107 for reference is adjusted by controlling a trimming circuit 108. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
