| 摘要 |
In the nonvolatile semiconductor memory device of this invention, a program control circuit 1 sets the threshold value of a first reference cell RFC0 by means of a write circuit WC on the basis of a result of comparing the threshold value of the first reference cell RFC0 with the threshold value of a second reference cell SRC executed by a sense amplifier 8 for trimming. The compare of threshold values by the sense amplifier 8 for trimming can be executed within a shorter time than in the threshold value read operation of the first reference cell RFC0. Therefore, when the number of the first reference cells is increased, the threshold value adjustment time can be remarkably reduced in comparison with the prior art in which the threshold value of the first reference cell is adjusted by reading the first reference cell.
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