A data storage device includes a nonvolatile memory device; a control unit configured to generate a descriptor in which works for controlling the nonvolatile memory device are written; a memory control unit configured to provide control signals and write data to the nonvolatile memory device based on the descriptor; and a voltage detector configured to provide a voltage drop signal to the memory control unit in the case where a first operating voltage provided to the memory control unit or a second operating voltage provided to the nonvolatile memory device, drops.