Electronic device having ecc decoder

A memory system comprising:

• a controller;
• and
• a memory device including a memory cell array and configured to
• generate a delta bit data by performing a logic operation on a hard data chunk and a soft data chunk, the hard data chunk being read by a hard decision read voltage from a specific region of the memory cell array, the soft data chunk being read by a soft decision read voltage from the specific region, the soft decision read voltage being different from the hard decision read voltage by a preset offset, and
• provide the controller with the hard data chunk and the delta bit data other than the soft decision read voltage;
• and
• wherein the controller includes:
• a soft syndrome generator configured to generate a soft syndrome by performing a logic operation on a hard syndrome for the hard data chunk and a delta syndrome for the delta bit data;
• and
• a data determiner configured to determine whether to restore the soft data chunk based on a result of comparing a syndrome weight of the hard syndrome with a syndrome weight of the soft syndrome.