Data storage device and method of operating the same

1. A data storage device comprising:

a storage configured to store data; and

a controller configured to perform a normal read operation based on a default read voltage in accordance with a read request of a host device and to perform a read retry operation using at least one retry read voltage when the normal read operation fails,

wherein the controller comprises:

a hit ratio table configured to store read success records as hit ratios of retry read voltages in association with workloads, each workload being associated with a set of retry read voltages; and

a read voltage determiner configured to determine the workload when the normal read operation fails and to select the set of retry read voltages associated with the determined workload, the retry read voltages in the selected set being ordered from a highest hit ratio to a lowest hit ratio,

wherein the hit ratio is the number of successful retry reads for each retry read voltage with respect to a total number of successful retry reads, and

the read voltage determiner is configured to determine the workload according to at least one of an address of the storage provided with the read request of a host device or a size of data to be read according to the read request of a host.

2. The data storage device of claim 1 , wherein the read voltage determiner is configured to update the hit ratio table in accordance with results of the read retry operation.

3. The data storage device of claim 1 , wherein the determined workload comprises one of a sequential read operation performed in response to a start logical address immediately following a last logical address of a previous read operation, a random read operation corresponding to a read operation performed in response to a random logical address, and a small read operation of data of a size no more than a set size.

4. A data storage device comprising:

a storage configured to store data; and

a controller configured to control the storage,

wherein the controller comprises:

a read retry table configured to store a plurality of retry read voltages;

a hit ratio table configured to store read success records as hit ratios of the retry read voltages in association with workloads; and

a read voltage determiner configured to determine the workload when a normal read operation using a default read voltage fails and to select read voltages based on the hit ratios of the retry read voltages associated with the determined workload,

wherein the hit ratio is the number of successful retry reads for each retry read voltage with respect to a total number of successful retry reads, and

the read voltage determiner is configured to determine the workload according to at least one of an address of the storage provided with the read request of a host device or a size of data to be read according to the read request of a host.

5. The data storage device of claim 4 , wherein the read voltage determiner is configured to update the hit ratio table in accordance with results of a read retry operation.

6. A method of operating a data storage device including a storage configured to store data and a controller configure to control the storage, the controller including a hit ratio table configured to store read success records as hit ratios of retry read voltages in association with workloads, each workload being associated with a set of retry read voltages, the method comprising:

performing, by the controller, a normal read operation based on a default read voltage in accordance with a read request of a host device; and

performing, by the controller, a read retry operation using at least one retry read voltage when the normal read operation fails,

wherein the performing of the read retry operation comprises:

determining, by the controller, a workload when the normal read operation fails;

selecting, by the controller, the set of retry read voltages associated with the determined workload, the retry read voltages in the selected set being ordered from a highest hit ratio to a lowest hit ratio; and

providing, by the controller, to the storage the selected set of retry read voltages to read data,

wherein the hit ratio is the number of successful retry reads for each retry read voltage with respect to a total number of successful retry reads, and

the controller is configured to determine the workload according to at least one of an address of the storage provided with the read request of a host device or a size of data to be read according to the read request of a host.

7. The method of claim 6 , further comprising updating, by the controller, the hit ratio table in accordance with results of the read retry operation.

8. The method of claim 6 , wherein the determined workload comprises one of a sequential read operation performed in response to a start logical address immediately following a last logical address of a previous read operation, a random read operation corresponding to a read operation performed in response to a random logical address, and a small read operation of data of a size no more than a set size.

9. An operating method of a controller, the operating method comprising:

determining a workload of a data storage device when a previous read operation fails;

controlling a storage to perform a subsequent read operation with one or more read retry voltages of a selected set of read retry voltages that are associated with the determined workload, the selected set of read retry voltages being ordered according to hit ratios thereof; and

updating the hit ratios when the subsequent read operation is successful,

wherein the data storage device includes the controller and the storage,

wherein the hit ratio is the number of successful retry reads for each retry read voltage with respect to a total number of successful retry reads, and

the workload is determined according to at least one of an address of the storage provided with the read request of a host device or a size of data to be read according to the read request of a host.