Semiconductor memory device managing flexible refresh skip area

A memory system comprising:

• a memory device comprising a memory cell array;
• and
• a memory controller configured to set a refresh skip area of the memory cell array,
• wherein the memory device is further comprises a refresh control circuit configured to control a refresh operation on a memory area of the memory cell array that is to be refreshed and does not include the refresh skip area of the memory cell array.

A method of operating a memory device, the method comprising:

• receiving and storing a beginning address and an end address of a memory area of a memory cell array that is to be refreshed from a memory controller;
• setting a minimum counting value of a refresh counter to the beginning address and setting a maximum counting value of the refresh counter to the end address;
• and
• receiving a refresh command from the memory controller and performing a refresh operation on the memory area that is to be refreshed and does not include a refresh skip area of the memory cell array.