| 摘要 |
<p>PROBLEM TO BE SOLVED: To mutually and linearly control a threshold and the voltage to be impressed to each electrode corresponding to such threshold by applying a current to the channel between the drain and source of the selected memory cell and then impressing, to the drain, source and control gate, the voltage corresponding to the predetermined memory condition sufficient for moving charges. SOLUTION: In order to select the predetermined cells to be programmed, a signal corresponding to the address of predetermined cell is impressed to a bit line selecting means 14. A start signal PS is impressed to the first, second and third voltage sources 11, 12, 15 and the voltages VC, VD, VS are respectively impressed to the first, second and third voltage sources 11, 12, 15 so that the first, second and third voltage sources 11, 12, 15 respectively coupled with the control gate, drain and source of cell correspond to the threshold level programmed by the program start signal PS. When the programming starts, an inverted area is formed between the drain and source and thereby a current starts to flow.</p> |
