1. A nonvolatile memory device, comprising: a data conversion unit, wherein the data conversion unit comprises: an encoder configured to set data for each of a plurality of word lines and to create second data to be programmed into a plurality of memory cells by performing a logical operation on the set data and first data input for programming; and a decoder configured to create the first data by performing a logical operation on the second data that is read from the memory cells and the set data.