Patent ID: 6958938

Claim:
A data writing method for a semiconductor memory device having a first memory cell block capable of rewriting data and having at least one first memory cell; and a second memory cell block capable of rewriting data and having at least one second memory cell adjoining said first memory cell, said method comprising: writing data into said first memory cell; rewriting the data into said first memory cell when an insufficiency of the data of said first memory cell is determined as a result of verifying the data of said first memory cell at one first reference threshold voltage; writing data into said second memory cell following writing the data into said first memory cell; and rewriting the data into said first memory cell following writing the data into said second memory cell when an insufficiency of the data of said first memory cell is determined as a result of verifying the data of said first memory cell at one second reference threshold voltage, and said first reference threshold voltage is set to be different from said second reference threshold voltage.