| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a multi-level flash memory programming method using a sensing circuit and a reading-method therefor. SOLUTION: First word line voltage Vp1 is applied to a memory cell and a reference cell (S102). Vp1 is intermediate voltage which is higher than a threshold voltage of a cell and lower than a threshold voltage of a third level. When Vp1 is applied, a first cell is specified (S103), further, it is decided whether the cell is programmed or not (S104). A program is performed by an automatic verification program method to raise the threshold voltage of the cell to a second level (S105). Further, when the prescribed operation is all completed based on data stored in a register, a cell number is increased (S106), a second level program stage is finished, and operation is shifted to a third level program stage (S107).</p> |
