Multi-level nonvolatile semiconductor memory device having improved programming level and read/write multi-level data circuits

摘要

A nonvolatile semiconductor memory device includes a memory cell including a charge storage section for storing n-value data (n3). In this device, the charge storage section has discrete first to n-th charge amount regions for storing the n-value data. If the first to n-th charge amount regions are defined as n-th, (n-1)-th, . . . , (i+1)-th, i- th charge amount regions descending order of an amount of positive or negative charge stored in the charge storage section, a charge amount difference Mj between a j-th charge amount region and a (j-1)-th charge amount region is set to Mn Mn-1 . . . Mi+2 Mi+1.