Patent ID: 11894074
Assignee: KIOXIA CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 4:
5. The device of claim 1, wherein
the states include a third state and a fourth state, the fourth state is higher than the third state, a memory cell transistor whose threshold voltage is included in the third state stores third data, and a memory cell transistor whose threshold voltage is included in the fourth state stores fourth data,
in a verify operation of the third data, during application of a verify high voltage of the third data to the word line, the controller is configured to determine whether or not a threshold voltage of a memory cell transistor to which the third data is to be written exceeds the verify high voltage, and also determine whether or not a threshold voltage of a memory cell transistor to which the fourth data is to be written exceeds the verify low voltage, and
states set between the first state and the second state are different in number from states set between the third state and the fourth state.