| 摘要 |
PROBLEM TO BE SOLVED: To obtain a multi-level type semiconductor non-volatile memory device which can read multi-level data under a large and stable read operation margin. SOLUTION: In a semiconductor non-volatile memory device for recording binary digital data of two bits in one memory transistor, data read means 6 to 8, CMP, Dr1, Dr2 are provided in order to set the 3-level read word line voltages VR1 to VR3 to judge the binary digital data [D2, D1] recorded previously to the read memory transistor and read the data by sequentially and selectively switching the optimum read word line voltage of VR1 to VR3 so that data contents are sequentially judged to the bit D1 of the LSB side from the bit D2 of the MSB side of the binary digital data during the data read operation. |
