Nonvolatile semiconductor memory device

摘要

A multi-value storing EEPROM having data-storing circuits (9), each storing a control data item which determines a write-control voltage to be applied to one bit line (BL) in order to write data into any memory cell (M) connected to the bit line (BL). The write-control voltage is applied to the bit line (BL) to write data into the memory cell (M), on the basis of the control data item stored in the data-storing circuit (9). To read the data from the cells (M), a bit-line signal is supplied to the bit line (BL) in accordance with the control data item stored in the data-storing circuit (9). To achieve write verification, the value of the bit-line signal on the bit line (BL) is detected from the data-storing state the memory cell assumes. The control data item stored in the circuit can be changed on the basis of the data-storing state of the memory cell (M). <IMAGE>