Memory controller, data storage device, and memory controlling method

A memory controller for a nonvolatile memory, comprising:

• a first error detection code generator to generate a first error detection code associated with data received from a host;
• a controller for writing the data and the first error detection code to the nonvolatile memory, and for reading the data and the first error detection code from the nonvolatile memory when the data is requested to be read by the host;
• an error detector that performs an error detection based on the data and the first error detection code which are read from the nonvolatile memory;
• a second error detection code generator to generate a second error code based on the data read from the nonvolatile memory;
• and
• a mismatch code generator to generate a mismatch code signaling the presence of errors in the data read from the nonvolatile memory,
• wherein either the second error detection code or the mismatch code is selected and added to the data read from the nonvolatile memory and sent to the host with the data read from the nonvolatile memory.