Data storage device and operating method thereof

1. A data storage device comprising:

a storage medium including a plurality of memory units; and

a controller suitable for performing a state determination operation to first memory units in order of a write sequence until a memory unit stored with an error-correction-failed data when a power supply is restored after an abnormal power-off, skipping the state determination operation to second memory units between the memory unit storing the error-correction-failed data and a pointed memory unit, performing the state determination operation to third memory units after the pointed memory unit in order of the write sequence, and performing a garbage collection operation to the first to third memory units after completion of all of the state determination operations,

wherein the second memory units are memory units for which mapping update is completed before the abnormal power-off occurs, and the third memory units are memory units for which mapping update is not completed before the abnormal power-off occurs.

2. The data storage device according to claim 1 , wherein, when performing the state determination operation, the controller determines new and error-correction-successful data of each memory unit as in a first state, and determines old or error-correction-failed data of each memory unit as in a second state.

3. The data storage device according to claim 2 , wherein, when performing the garbage collection operation, the controller determines new data in the first state in each memory unit as valid data, and determines the data in the second state in each memory unit or old data in the first state in each memory unit as invalid data.

4. The data storage device according to claim 2 , wherein, when performing the garbage collection operation, the controller determines new and error-correction-successful data of each second memory unit as valid data, and determines old or error-correction-failed data of each second memory unit as invalid data.

5. The data storage device according to claim 1 , wherein, when performing the garbage collection operation, the controller classifies data stored in the first to third memory units into valid data and invalid data, moves the valid data to other memory units, and performs an erase operation to the first to third memory units.

6. The data storage device according to claim 1 , wherein the controller performs the state determination operation to the third memory units in order of the write sequence until an empty memory unit Is detected.

7. A method for operating a data storage device, comprising:

performing a state determination operation to first memory units in order of a write sequence until a memory unit stored with an error-correction-failed data after a power supply is restored after an abnormal power-off;

skipping the state determination operation to second memory units between the memory unit storing the error-correction-failed data and a pointed memory unit;

performing the state determination operation to third memory units after the pointed memory unit in order of the write sequence; and

performing a garbage collection operation to the first to third memory units after completion of all of the state determination operations,

wherein the second memory units are memory units for which mapping update is completed before the abnormal power-off occurs, and the third memory units are memory units for which mapping update is not completed before the abnormal power-off occurs.

8. The method according to claim 7 , wherein the performing of the state determination operation comprises:

determining new and error-correction-successful data of each memory unit as in a first state; and

determining old or error-correction-failed data of each memory unit as in a second state.

9. The method according to claim 8 , wherein the performing of the garbage collection operation comprises:

determining new data in the first state in each memory unit as valid data; and

determining the data in the second state in each memory unit or old data in the first state in each memory unit as invalid data.

10. The method according to claim 7 , wherein the performing of the garbage collection operation comprises:

determining new and error-correction-successful data of each second memory unit as valid data; and

determining old or error-correction-failed data of each second memory unit as invalid data.

11. The method according to claim 7 , wherein the performing of the garbage collection operation comprises:

classifying data stored in the first to third memory units, into valid data and invalid data;

moving the valid data to other memory units; and

performing an erase operation to the first to third memory units.

12. The method according to claim 7 , wherein the state determination operation is performed to the third memory units in order of the write sequence until an empty memory unit is detected.

13. A method for operating a data storage device, comprising:

performing a state determination operation to a plurality of memory units in order of a write sequence after a power supply is restored after an abnormal power-off; and

performing a garbage collection operation to the memory units after completion of all of the state determination operations,

wherein the state determination operation is skipped for memory units for which mapping update is completed before the abnormal power-off occurs, and

wherein the memory units for which the state determination operation is performed are memory units for which mapping update is not completed before the abnormal power-off occurs.

14. The method according to claim 13 , wherein the performing of the state determination operation comprises:

determining new and error-correction-successful data of each memory unit as in a first state; and

determining old or error-correction-failed data of each memory unit as in a second state.

15. The method according to claim 14 , wherein the performing of the garbage collection operation comprises:

determining new data in the first state in each memory unit as valid data; and

determining the data in the second state in each memory unit or old data in the first state in each memory unit as invalid data.

16. The method according to claim 13 , wherein the performing of the garbage collection operation comprises:

determining new and error-correction-successful data of each memory unit for which the state determination operation is skipped as valid data; and

determining old or error-correction-failed data of each memory unit for which the state determination operation is skipped as invalid data.

17. The method according to claim 13 , wherein the state determination operation is performed to the memory units in order of the write sequence until an empty memory unit is detected.