ELECTRICALLY REWRITABLE NON-VOLATILE SEMICONDUCTOR STORAGE

摘要

PROBLEM TO BE SOLVED: To provide a non-volatile semiconductor storage that can store parallel writing data quickly and can be electrically rewritten. SOLUTION: A non-volatile semiconductor storage is provided with a memory cell for storing data, word and bit lines connected to the memory cell, and a threshold voltage change means for changing the threshold voltage of the memory cell to three kinds or more. The threshold voltage change means has variable voltage circuits 1a-1h for a row line for applying one kind of voltage to the above word line for one kind of threshold voltage, and variable voltage generation circuits 2a-2h for applying one kind of voltage to the above bit line for one kind of the threshold voltage.