Semiconductor device and method for driving semiconductor device

A semiconductor device comprising:

• memory cells each comprising a first transistor including an oxide semiconductor and a second transistor including a material other than the oxide semiconductor;
• a driver circuit configured to drive the memory cells;
• and
• a potential generating circuit configured to generate potentials supplied to the driver circuit,
• wherein the driver circuit comprises:
• a data buffer configured to hold a first data to be written into the memory cells;
• a writing circuit configured to write a second data with one potential of the potentials into the memory cells in accordance with the first data;
• a reading circuit configured to read the second data written into the memory cells;
• and
• a verifying circuit configured to verify whether the second data agrees with the first data or not,
• wherein the one potential is a write potential for a part of the memory cells where the second data agree with the first data;
• and
• wherein the write potential is changed to another potential of the potentials, for the others of the memory cells where the second data does not agree with the first data.

A method for driving a semiconductor device comprising a memory cell comprising a first transistor including an oxide semiconductor and a second transistor including a material other than the oxide semiconductor, the method comprising the steps of:

• holding a first data to be written into the memory cell in a data buffer;
• writing a second data with one potential of potentials into the memory cell in accordance with the first data;
• reading the second data written into the memory cell;
• verifying whether the second data agrees with the first data or not;
• and
• determining the one potential as a first write potential for the memory cell where the second data agrees with the first data, or changing the first write potential to another potential of the potentials, for the memory cell where the second data does not agree with the first data.

A method for driving a semiconductor device comprising memory cells each comprising a first transistor including an oxide semiconductor and a second transistor including a material other than the oxide semiconductor, the method comprising the steps of:

• holding a first data to be written into the memory cells in a data buffer;
• writing a second data with one potential of potentials into the memory cells in accordance with the first data;
• reading the second data written into the memory cells;
• verifying whether the second data agrees with the first data or not;
• determining the one potential as a first write potential for a first part of the memory cells where the second data agrees with the first data;
• and
• changing the first write potential to another potential of the potentials, for a second part of the memory cells where the second data does not agree with the first data.