Storage device configured to write data based on write energy and method of operating the same

A storage device comprising:

• a nonvolatile memory device comprising a memory cell array, the memory cell array comprising a user area and a power loss protection (PLP) area;
• and
• a storage controller configured to, based on sudden power-off being detected, write first PLP data in a first memory cell connected to a first word line, write dummy data in a second memory cell connected to a second word line of the PLP area, and write second PLP data in a third memory cell connected to a third word line of the PLP area, which is adjacent to the second word line, and having second write energy,
• wherein the second word line is adjacent each of the first word line and the third word line, and
• wherein a first write energy of the first memory cell is less than a second write energy of the second memory cell.

A storage device comprising:

• a nonvolatile memory device comprising a memory cell array, the memory cell array comprising a plurality of cell strings extending along a direction perpendicular to a substrate, wherein each of the plurality of cell strings comprises at least one string selection transistor, a plurality of memory cells connected in series, and at least one ground selection transistor;
• and
• a storage controller configured to write first user data in a first memory cell from among the plurality of memory cells and write second user data in a second memory cell from among the plurality of memory cells,
• wherein a first write energy of the first memory cell is less than a second write energy of the second memory cell.