Operation method of controller configured to control nonvolatile memory device and operation method of storage device

1. An operation method of a controller which is configured to control a nonvolatile memory device, the method comprising:

receiving cell counting data associated with selected memory cells included in the nonvolatile memory device from the nonvolatile memory device, wherein the receiving of the cell counting data associated with the selected memory cells included in the nonvolatile memory device from the nonvolatile memory device includes:

transmitting a first cell-counting command to the nonvolatile memory device; and

receiving the cell counting data from the nonvolatile memory device;

adjusting operation parameters of the nonvolatile memory device based on the cell counting data;

performing a valley search operation for the selected memory cells based on the adjusted operation parameters; and

performing a read operation for the selected memory cells based on a result of the valley search operation.

2. The method as claimed in claim 1 , wherein the operation parameters include starting levels and offsets used in the valley search operation.

3. The method as claimed in claim 1 , wherein the adjusting of the operation parameters of the nonvolatile memory device based on the cell counting data includes:

detecting a degradation state of the selected memory cells based on the cell counting data; and

controlling the operation parameters based on the degradation state.

4. The method as claimed in claim 3 , wherein, when the degradation state indicates a charge loss state, a starting level of the operation parameters is decreased, and

wherein, when the degradation state indicates a charge gain state, the starting level of the operation parameters is increased.

5. The method as claimed in claim 3 , wherein, when the degradation state indicates that a distance between adjacent program states decreases, an offset of the operation parameters is decreased, and

wherein, when the degradation state indicates that the distance between the adjacent program states increases, the offset of the operation parameters is increased.

6. The method as claimed in claim 3 , wherein the controlling of the operation parameters based on the degradation state includes:

adjusting the operation parameters based on the degradation state; and

transmitting a set feature command including information about the adjusted operation parameters to the nonvolatile memory device.

7. The method as claimed in claim 3 , wherein the degradation state of the selected memory cells is detected based on the cell counting data and at least one of a read count, an erase count, a program state, and a cell type associated with the selected memory cells.

8. The method as claimed in claim 7 , wherein the degradation state is detected based on machine learning or an adaptive algorithm.

9. The method as claimed in claim 1 , wherein the performing of the read operation for the selected memory cells based on the result of the valley search operation includes:

determining optimal read levels based on the result of the valley search operation; and

performing the read operation for the selected memory cells by using the optimal read levels.

10. The method as claimed in claim 9 , wherein the performing of the read operation for the selected memory cells by using the optimal read levels includes:

transmitting a set feature command including information about the optimal read levels to the nonvolatile memory device;

transmitting an address corresponding to the selected memory cells and a read command to the nonvolatile memory device; and

receiving data that is read using the optimal read levels, from the nonvolatile memory device.

11. The method as claimed in claim 9 , further comprising:

before receiving the cell counting data associated with the selected memory cells from the nonvolatile memory device, performing a read operation for the selected memory cells using a plurality of read voltages; and

correcting an error of data read by the read operation using the plurality of read voltages.

12. An operation method of a controller which is configured to control a nonvolatile memory device, the method comprising:

receiving cell counting data associated with selected memory cells included in the nonvolatile memory device from the nonvolatile memory device;

adjusting operation parameters of the nonvolatile memory device based on the cell counting data, wherein the adjusting of the operation parameters of the nonvolatile memory device based on the cell counting data includes:

detecting a degradation state of the selected memory cells based on the cell counting data; and

controlling the operation parameters based on the degradation state;

performing a valley search operation for the selected memory cells based on the adjusted operation parameters; and

performing a read operation for the selected memory cells based on a result of the valley search operation.

13. The method as claimed in claim 12 , wherein the operation parameters include starting levels and offsets used in the valley search operation.

14. The method as claimed in claim 12 , wherein, when the degradation state indicates a charge loss state, a starting level of the operation parameters is decreased, and wherein, when the degradation state indicates a charge gain state, the starting level of the operation parameters is increased.

15. The method as claimed in claim 12 , wherein, when the degradation state indicates that a distance between adjacent program states decreases, an offset of the operation parameters is decreased, and

wherein, when the degradation state indicates that the distance between the adjacent program states increases, the offset of the operation parameters is increased.

16. The method as claimed in claim 12 , wherein the controlling of the operation parameters based on the degradation state includes:

adjusting the operation parameters based on the degradation state; and

transmitting a set feature command including information about the adjusted operation parameters to the nonvolatile memory device.

17. The method as claimed in claim 12 , wherein the degradation state of the selected memory cells is detected based on the cell counting data and at least one of a read count, an erase count, a program state, and a cell type associated with the selected memory cells.

18. The method as claimed in claim 17 , wherein the degradation state is detected based on machine learning or an adaptive algorithm.

19. An operation method of a controller which is configured to control a nonvolatile memory device, the method comprising:

receiving cell counting data associated with selected memory cells included in the nonvolatile memory device from the nonvolatile memory device;

adjusting operation parameters of the nonvolatile memory device based on the cell counting data;

performing a valley search operation for the selected memory cells based on the adjusted operation parameters; and

performing a read operation for the selected memory cells based on a result of the valley search operation, wherein the performing of the read operation for the selected memory cells based on the result of the valley search operation includes:

determining optimal read levels based on the result of the valley search operation; and

performing the read operation for the selected memory cells by using the optimal read levels.

20. The method as claimed in claim 19 , wherein the performing of the read operation for the selected memory cells by using the optimal read levels includes:

transmitting a set feature command including information about the optimal read levels to the nonvolatile memory device;

transmitting an address corresponding to the selected memory cells and a read command to the nonvolatile memory device; and

receiving data that is read using the optimal read levels, from the nonvolatile memory device.