| 摘要 |
<p>PURPOSE: To realize a non-volatile semiconductor memory device which is capable of enhancing non-volatile multi-valued memories of small window in memory holding properties, frequency of rewrite, and substantial yield. CONSTITUTION: Multi-valued memory cells 2 capable of storing multi values, reference cells 16a, 16b, 16c, 16d,... capable of storing multi values different from those of the memory cells 2 and specified in number corresponding to the number of the stored multi values, an intermediate value generating circuit 30 which generates an intermediate current value between the current outputs of, at least, two cells out of the reference cells 16a, 16b, 16c, 16d,... when the data are read out from the multi-valued memory cells 2, and a comparison discriminating circuit 32 which discriminates data stored in the multi-valued memory cells 2 comparing the output of the intermediate value generating circuit 30 with those of the multi-valued memory cells 2 are provided.</p> |
