Memory system for removing memory cell fault and method thereof

A method for controlling a memory system including a memory device provided with a plurality of ranks, comprising:

• performing an Error Correction Code (ECC) operation onto plural data stored in, or outputted from, at least one rank of the memory device in parallel;
• deciding a plurality of refresh cycles that respectively correspond to combinations of the plurality of ranks and at least one program executed onto the memory device based on a performance diagnosis result of each of the ranks when the program is executed;
• and
• controlling a refresh operation to be performed onto the at least one rank based on the decided refresh cycles to cure an ECC uncorrectable error while the ECC operation is performed.

A memory system, comprising:

• a memory device including a plurality of ranks;
• and
• a memory controller suitable for diagnosing a performance each of the ranks when the program is executed, to cure an ECC uncorrectable error while the ECC operation is performed,
• wherein a memory controller determines a plurality of refresh cycles, each corresponding to at least one of various combinations regarding the plurality of ranks and at least one program executed onto the memory device, based on a diagnosis result, to control a refresh operation to be performed onto the ranks based on the decided refresh cycles.