Multilevel storage nonvolatile semiconductor memory device enabling high-speed data reading and high-speed data writing

摘要

A nonvolatile semiconductor memory device transmits/receives data to/from a data input/output terminal every j bits (e.g., eight bits). Each of memory cells in a memory cell array can hold data of n bits in correspondence to 2n threshold levels. A write data conversion circuit generates write data from bit data input from the same data input/output terminal in a set of a plurality of data of j bits input at different timings.