In the operation of writing the second page, the control circuit precharges the
bit line in verifying data "2" in the memory cell when the DDC has data "1" in
it after the data cache is set and does not precharge the bit line when the DDC
has data "0" in it. As a result, when data "2" has been written into the memory
cell, the bit line is at the intermediate potential, which raises the threshold
voltage of the memory cell a little.
