| 摘要 |
<p>PROBLEM TO BE SOLVED: To eliminate the need for control for each bit line by alternately applying a gate writing voltage, a grounding voltage, or a self-discharge voltage that is higher than the gate writing voltage to a word line being connected to the gate of a memory cell in open state after charging the bit line being connected to a drain to a drain writing voltage. SOLUTION: After a bit line being connected to the drain of a memory cell to be written is charged to a drain writing voltage, a gate writing voltage and a grounding voltage or a self-discharge voltage that is higher than the gate writing voltage are alternately applied to a word line while the bit line is in open state. When the threshold voltage of the memory cell reaches a grounding potential or the gate writing voltage, the memory cell conducts electricity and the charging charge of the bit line is discharged when a grounding potential or a voltage that is higher than the gate writing voltage is applied to the word line, thus reducing the drain writing voltage and stopping a writing operation.</p> |
