| 摘要 |
<p>PURPOSE:To shorten a writing time and to increase the number of the times of rewriting by impressing a voltage on a lower potential side compared with the voltage impressed to a control gate to a drain when a charge is made into an accumulating condition, and impressing the voltage on a high voltage side equivalent to a prescribed potential difference when the charge is made into a depletion condition. CONSTITUTION:When the charge of a floating gate 12 is made into the accumulating condition, the voltage on the lower potential side compared with the voltage impressed to a control gate 11 is impressed to a drain 13. Further, when it is made into the depletion condition, the voltage on the high voltage side equivalent to the potential difference between the voltage impressed to the control gate 11 and the voltage on the low potential side is impressed to the drain 13. Consequently, an erasing action and a programming action are simultaneously carried out, the writing time is made into the half of the ordinary time, and the erasing or programming action is carried out per writing action. Thus, the writing time can be shortened, and the number of the times of the rewriting can be increased.</p> |
