Data storage device and operating method thereof

1. A data storage device comprising:

a memory device including memory regions classified into a plurality of memory groups, each of the plurality of memory groups corresponding to a plurality of read bias voltage groups, each of the plurality of read bias voltage groups including read bias voltage sets, each of the read bias voltage sets including read bias voltages which are expected to be respectively positioned between threshold voltage distributions of memory cells of the memory regions; and

a controller configured to:

perform, for a target memory region a read retry operation based on a first read bias voltage group corresponding to a memory group in which the target memory region is included,

select at least one of remaining read bias voltage groups excluding the first read bias voltage group among the plurality of read bias voltage groups, according to a result of the read retry operation, and

perform an additional read retry operation for the target memory region based on the at least one of remaining read bias voltage groups.

2. The data storage device according to claim 1 , wherein the controller performs the read retry operation by reading data from the target memory region based on a read bias voltage set included in the first read bias voltage group, performing an error correction operation for the data, and iterating reading of new data based on an unused read bias voltage set included in the first read bias voltage group and performing of an error correction operation for the new data according to a result of the error correction operation for the data.

3. The data storage device according to claim 1 , wherein the controller performs the read retry operation until an error correction operation for data read from the target memory region based on read bias voltage sets included in the first read bias voltage group succeeds.

4. The data storage device according to claim 1 , wherein the controller performs the read retry operation until all error correction operations for data read from the target memory region based on the read bias voltage sets fail.

5. The data storage device according to claim 1 , wherein the controller selects an optimal read bias voltage set among read bias voltage sets included in the first read bias voltage group, according to results of error correction operations performed in the read retry operation, and selects a read bias voltage group for the additional read retry operation, based on separations of the remaining read bias voltage groups with respect to the optimal read bias voltage set.

6. A data storage device comprising:

a memory device including a plurality of memory regions which are classified into a plurality of memory groups, each of the plurality of memory groups corresponding to a plurality of read bias voltage groups, each of the plurality of read bias voltage groups including read bias voltage sets, each of the read bias voltage sets including read bias voltages which are expected to be respectively positioned between threshold voltage distributions of memory cells of the memory regions; and

a controller configured to perform, for a target memory region, a read retry operation based on a first read bias voltage group among the plurality of read bias voltage groups, corresponding to a first memory group in which the target memory region is included, determine error estimation indexes respectively corresponding to read bias voltage sets included in the first read bias voltage group, according to a result of the read retry operation, select a second read bias voltage group corresponding to a second memory group among the plurality of read bias voltage groups, based on the error estimation indexes, and perform an additional read retry operation for the target memory region, based on the second read bias voltage group.

7. The data storage device according to claim 6 , wherein the controller performs the read retry operation by reading data from the target memory region based on a read bias voltage set included in the first read bias voltage group, performing an error correction operation for the data, and iterating reading of new data based on an unused read bias voltage set included in the first read bias voltage group and performing of an error correction operation for the new data, according to a result of the error correction operation for the data.

8. The data storage device according to claim 6 , wherein the controller performs the read retry operation until an error correction operation for data read from the target memory region based on the read bias voltage sets succeeds.

9. The data storage device according to claim 6 , wherein the controller performs the read retry operation until all error correction operations for data read from the target memory region based on the read bias voltage sets fail.

10. The data storage device according to claim 6 , wherein the controller determines the error estimation indexes based on syndromes with respect to data read from the target memory region based on the read bias voltage sets.

11. The data storage device according to claim 6 , wherein the controller selects an optimal read bias voltage set among the read bias voltage sets based on the error estimation indexes, determines separations of the plurality of read bias voltage groups with respect to the optimal read bias voltage set, and selects the second read bias voltage group based on the separations.

12. The data storage device according to claim 11 , wherein the controller determines each of the separations based on differences between read bias voltage sets included in a corresponding read bias voltage group and the optimal read bias voltage set.

13. The data storage device according to claim 6 ,

wherein the controller classifies the memory regions into the plurality of memory groups according to attributes of the memory regions, and

wherein the plurality of read bias voltage groups respectively correspond to the plurality of memory groups.

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

classifying, by a controller, memory regions of a memory device into a plurality of memory groups, each of the plurality of memory groups corresponding to a plurality of read bias voltage groups, each of the plurality of read bias voltage groups including read bias voltage sets, each of the read bias voltage sets including read bias voltages which are expected to be respectively positioned between threshold voltage distributions of memory cells of the memory regions;

performing, by the controller, for a target memory region, a read retry operation based on a first read bias voltage group among the plurality of read bias voltage groups, corresponding to a first memory group in which the target memory region is included;

determining, by the controller, error estimation indexes respectively corresponding to read bias voltage sets included in the first read bias voltage group, according to a result of the read retry operation;

selecting, by the controller, a second read bias voltage group corresponding to a second memory group among the plurality of read bias voltage groups, based on the error estimation indexes; and

performing, by the controller, an additional read retry operation based on the second read bias voltage group for the target memory region.

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

reading data from the target memory region based on a read bias voltage set included in the first read bias voltage group;

performing an error correction operation for the data; and

iterating reading of new data based on an unused read bias voltage set included in the first read bias voltage group and performing of an error correction operation for the new data, according to a result of the error correction operation for the data.

16. The method according to claim 14 , wherein the read retry operation is performed until an error correction operation for data read from the target memory region based on any one of the read bias voltage sets succeeds or all error correction operations for data read based on the read bias voltage sets fail.

17. The method according to claim 14 , wherein the error estimation indexes are determined based on syndromes with respect to data read from the target memory region based on the read bias voltage sets.

18. The method according to claim 14 , wherein the selecting of the second read bias voltage group comprises:

selecting an optimal read bias voltage set among the read bias voltage sets, based on the error estimation indexes;

determining separations of the plurality of read bias voltage groups with respect to the optimal read bias voltage set; and

selecting the second read bias voltage group based on the separations.

19. The method according to claim 18 , wherein each of the separations is determined based on differences between read bias voltage sets included in a corresponding read bias voltage group and the optimal read bias voltage set.

20. The method according to claim 14 , further comprising:

classifying memory regions into a plurality of memory groups, according to attributes of the memory regions,

wherein the plurality of read bias voltage groups respectively correspond to the plurality of memory groups.