A method of operating a memory controller that performs decoding by using a parity check matrix corresponding to a convolution-type low density parity check (LDPC) code includes receiving a codeword from at least one memory device, the codeword including a first sub-codeword and a second sub-codeword; decoding a first sub-codeword into first data by using first sliding windows in a first direction, set based on a first sub-matrix included in the parity check matrix and associated with the first sub-codeword; and decoding a second sub-codeword into second data by using second sliding windows in a second direction, set based on a second sub-matrix included in the parity check matrix and associated with the second sub-codeword.