Nonvolatile semiconductor memory including memory cell for storing multilevel data having two or more values

Abstract

A write controller performs verification for checking whether each memory cell is on a predetermined verification level. For a memory cell to be written to a voltage level higher than the predetermined verification level, the write controller stores, in first and second latch circuits, the number of times of write to be performed by a write voltage after the verification. Whenever write is performed by the write voltage, the write controller updates the number of times of write stored in the first and second latch circuits. After write is performed the number of times of write by the write voltage, the write controller performs write by an intermediate voltage lower than the write voltage.