Memory system for removing memory cell fault and method thereof

A method for operating a memory controller for controlling an operation of a memory device including a plurality of ranks, comprising:

• performing an Error Correction Code (ECC) operation onto a data stored in, or outputted from, at least one rank of the memory device;
• deciding selection signals, each of which selects one command set corresponding to each of combinations of the ranks and at least one program executed in the memory device among a plurality of command sets;
• and
• executing a program including the selected command set in the memory device 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, electrically coupled to the memory device, suitable for curing an ECC uncorrectable error while the ECC operation is performed,
• wherein the memory controller determines selection signals, each for selecting a single command set, corresponding to at least one of various combinations regarding the plurality of ranks and at least one program executed in the memory device, among a plurality of command sets, to provide the single command set into the memory device.