A method of processing data using a memory controller includes determining at least one cell state to which each of a plurality of multi-level cells can be changed to based on a current cell state of each multi-level cell, where each multi-level cell includes a plurality of data pages; determining one of the data pages as having a stuck bit when a value of the data page has a single mapping value based on mapping values mapped to the at least one cell state and generating stuck bit data regarding the stuck bit; and encoding write data to be stored in the multi-level cells based on the stuck bit data.