Patent ID: 7079416

Claim:
A nonvolatile memory comprising: a plurality of memory cells; and a plurality of word lines, each of which couples to corresponding ones of said memory cells, wherein said nonvolatile memory is capable of receiving a plurality of commands which includes a write command accompanied with write address information, wherein, when said nonvolatile memory receives said write command accompanied with first address information as said write address information and first data, said nonvolatile memory selects a first word line according to said first address information, and stores said first data to said memory cells coupled to said first word line, wherein, after storing said first data and without erasing said first data stored in said memory cells when said nonvolatile memory receives said write command accompanied with second address information as said write address information and second data, said nonvolatile memory also selects said first word line according to said second address information, further modifying a storing state in said memory cells coupled to said first word line in response to said second data, wherein, after storing said first data, each of said memory cells coupled to said first word line has one state of a first state and a second state, said first and second states being discriminated by one threshold, and wherein, after modification of said storing state in said memory cells in response to said second data, each of said memory cells coupled to said first word line has one state of a third state, a fourth state, a fifth state and a sixth state, said third, fourth, fifth and sixth states being discriminated by three thresholds.