| 摘要 |
In a driving method of a semiconductor device which conducts a multilevel writing operation, a signal line for controlling on/off of a writing transistor for conducting a writing operation on a memory cell using a transistor including an oxide semiconductor layer is disposed along a bit line, and a multilevel writing operation is conducted with use of, also in a writing operation, a voltage which is applied to a capacitor at a reading operation. The potential of a bit line is detected while data writing is conducted, and thereby whether a potential corresponding to the written data is normally applied to the floating gate can be confirmed without a writing verify operation. |
