Method for reading multiple-value memory cells

摘要

A read method for multiple-value information in a semiconductor memory such as a nonvolatile semiconductor memory is introduced. The method includes obtaining a first data from a selected multiple-value memory cell by applying a first voltage to a control gate of the selected multiple-value memory cell. A second data from the selected multiple-value memory cell is obtained by applying a second voltage to the control gate of the selected multiple-value memory cell. A first bit of the plurality of bits stored in the selected multiple-value memory cell is then obtained by performing a predetermined calculation on the first data and the second data. A second bit of the plurality of bits is obtained from the selected multiple-value memory cell by applying a third voltage to the control gate of the selected multiple-value memory cell.