Patent attributes
An operation method of a nonvolatile memory device includes receiving a first DQ signal representing a first data bit from an external device through a first DQ line and receiving a second DQ signal representing a second data bit from the external device through a second DQ line, and programming a first memory cell corresponding to the first DQ line and a second memory cell corresponding to the second DQ line such that the first memory cell has any one of an erase state and a first program state based on the first DQ signal and the second memory cell has any one of the erase state and a second program state based on the second DQ signal. A lower limit value of a threshold voltage distribution corresponding to the second program state is higher than a lower limit value of a threshold voltage distribution corresponding to the first program state.
