Storage device and operating method thereof

A method for operating a storage device including a memory block including a plurality of pages, the method comprising:

• detecting a sudden power-off in which power supplied to the storage device is abnormally interrupted during a normal program operation on one page among the plurality of pages;
• and
• performing a dummy program operation on a selected page among the plurality of pages after the sudden power-off,
• wherein the normal program operation and the dummy program operation are performed by using an Incremental Step Pulse Program (ISPP) method, and
• wherein the dummy program operation is performed in a smaller number of program loops as compared with the normal program operation.

A memory controller for controlling a memory device including a memory block, the memory controller comprising:

• a power manager configured to generate power-off information when a sudden power-off is detected in which power supplied to the memory device is abnormally interrupted during a normal program operation on one page among the plurality of pages;
• and
• a program operation controller configured to control, when the power-off information is received, the memory device to perform a dummy program operation on a selected page among a plurality of pages included in the memory device after the sudden power-off,
• wherein the program operation controller controls the memory device to perform the normal program operation and the dummy program operation by using an Incremental Step Pulse Program (ISPP) method, and
• wherein the program operation controller controls the memory device to perform the dummy program operation in a smaller number of program loops as compared with the normal program operation.