Controller, memory system and operating method thereof

1. A controller for a memory system, the controller comprising:

a first map buffer and a second map buffer suitable for storing map data and hit counts respectively corresponding to the map data,

wherein each of the hit counts represents a number of accesses to data stored in a memory device by using a corresponding one among the map data,

wherein the controller swaps the map data and corresponding hit counts between the first and second map buffers such that the first map buffer stores relatively higher hit counts and corresponding map data than the second map buffer,

wherein the controller swaps the lowest hit counts and corresponding map data of the first map buffer and the highest hit counts and corresponding map data of the second map buffer, and

wherein the controller deletes the map data and corresponding hit counts from the second map buffer in order for the second map buffer to buffer data other than the map data and corresponding hit counts.

2. The controller of claim 1 , wherein the controller swaps the map data and corresponding hit counts when a new hit count and corresponding map data are stored in the first map buffer.

3. The controller of claim 1 , wherein the controller swaps the map data and corresponding hit counts during an idle state.

4. The controller of claim 1 , wherein the controller deletes the map data and corresponding hit counts from the second map buffer in a background state.

5. The controller of claim 4 , wherein the background state is one among states of a garbage collection operation, a wear leveling operation, a map flush operation and a bad block management operation.

6. An operation method of a controller, the method comprising:

storing map data and hit counts respectively corresponding to the map data into a first map buffer and a second map buffer,

swapping the map data and corresponding hit counts between the first and second map buffers such that the first map buffer stores relatively higher hit counts and corresponding map data than the second map buffer; and

deleting the map data and corresponding hit counts from the second map buffer in order for the second map buffer to buffer data other than the map data and corresponding hit counts,

wherein each of the hit counts represents a number of accesses to data stored in a memory device by using a corresponding one among the map data, and

wherein the swapping of the map data and corresponding hit counts includes swapping the lowest hit counts and corresponding map data of the first map buffer and the highest hit counts and corresponding map data of the second map buffer.

7. The method of claim 6 , wherein the swapping of the map data and corresponding hit counts is performed when a new hit count and corresponding map data are stored in the first map buffer.

8. The method of claim 6 , wherein the swapping of the map data and corresponding hit counts is performed during an idle state.

9. The method of claim 6 , the deleting of the map data and corresponding hit counts from the second map buffer is performed in a background state.

10. The method of claim 9 , wherein the background state is one among states of a garbage collection operation, a wear leveling operation, a map flush operation and a bad block management operation.

11. A memory system comprising:

a memory device suitable for storing data; and

a controller,

wherein the controller includes a first map buffer and a second map buffer suitable for storing map data and hit counts respectively corresponding to the map data,

wherein the controller swaps the map data and corresponding hit counts between the first and second map buffers such that the first map buffer stores relatively higher hit counts and corresponding map data,

wherein each of the hit counts represents a number of accesses to data stored in a memory device by using a corresponding one among the map data,

wherein the controller swaps the lowest hit counts and corresponding map data of the first map buffer and the highest hit counts and corresponding map data of the second map buffer, and

wherein the controller deletes the map data and corresponding hit counts from the second map buffer in order for the second map buffer to buffer data other than the map data and corresponding hit counts.

12. The memory system of claim 11 , wherein the controller swaps the map data and corresponding hit counts when a new hit count and corresponding map data are stored in the first map buffer.

13. The memory system of claim 11 , wherein the controller swaps the map data and corresponding hit counts during an idle state.

14. The memory system of claim 11 , wherein the controller deletes the map data and corresponding hit counts from the second map buffer in a background state.