Patent ID: 8085597

Claim:
A method for writing data to a nonvolatile semiconductor memory by injecting a charge to charge accumulation sections of memory cells of the nonvolatile semiconductor memory and writing multi-value data in which a data value corresponds to an amount of injected charge, the nonvolatile semiconductor memory having: a plurality of word lines; a plurality of memory cells, each of which having a plurality of charge accumulation sections, and having a MOSFET structure in which a gate terminal is connected to each of said word lines; and a plurality of bit lines connected to a drain terminal and a source terminal of each of said memory cells; the method comprising: applying the same gate voltage to each of the gate terminals of said plurality of memory cells via said word lines to designate the memory cells as a write target, simultaneously applying a write voltage that corresponds to each write data across drain-source terminals of two or more memory cells that are write targets via said bit lines to write simultaneously a plurality of data having mutually different data values to the memory cells.