Memory system having storage device and memory controller and operating method thereof

1. A memory system comprising:

a storage device including a plurality of pages for storing data; and

a memory controller configured to determine, when sudden power-off occurs, whether there is a high probability of a program disturb of unselected pages sharing a word line coupled to a selected page among the pages in rebooting, and output a command to perform an over-write operation for programming data in the selected page or skip the over-write operation, based on a result of the determination.

2. The memory system of claim 1 , wherein the memory controller:

determines whether a page, of which program operation is being performed when the sudden power-off occurs, exists among the pages; and

determines, when the page, of which program operation is being performed when the sudden power-off occurs, exists, the high probability of the program disturb of the unselected pages.

3. The memory system of claim 1 , wherein the memory controller includes:

a central processor unit configured to determine the high probability of the program disturb of the unselected pages, and output the command, based on a result of the determination; and

an error correction circuit configured to count an error bit number by detecting an error of data read from the storage device.

4. The memory system of claim 3 , wherein the central processor unit includes:

an operation detector configured to determine the high probability of the program disturb of the unselected pages, and output a signal, based on the determination result; and

a command generator configured to output the command in response to the signal.

5. The memory system of claim 4 , wherein the operation detector:

preferentially outputs, when a rebooting operation is started after the sudden power-off, a recovery signal; and

outputs, when a status result value is received from the storage device, a determination signal, according to the status result value.

6. The memory system of claim 5 , wherein the operation detector outputs any one of the recovery signal and the determination signal.

7. The memory system of claim 4 , wherein the command generator outputs, in response to the signal output from the operation detector, a read command for performing a read operation of the unselected pages; an over-write command for performing the over-write operation of the selected page; or an over-write skip command for skipping the over-write operation.

8. The memory system of claim 7 , wherein the storage device includes:

a command detector configured to output a read signal, an over-write signal or an over-write skip signal in response to the read command, the over-write command or the over-write skip command;

a read operation manager configured to output control signals for performing the read operation in response to the read signal;

an over-write operation manager configured to output the control signals for performing the over-write operation in response to the over-write signal; and

an over-write skip operation manager configured to output the control signals for skipping the over-write operation in response to the over-write skip signal.

9. The memory system of claim 8 , wherein, when the over-write skip command is input, the storage device newly selects a page different from the selected page, and outputs the control signals such that the over-write operation is performed on the newly selected page.

10. A method for operating a memory system, the method comprising:

performing rebooting after sudden power-off;

determining, in the rebooting, whether there is a high probability of a program disturb of unselected pages coupled to the same word line as a selected page;

performing, when it is determined that there is not the high probability of the program disturb, an over-write operation of writing data in the selected page; and

skipping, when it is determined that there is the high probability of the program disturb, the over-write operation of the selected page.

11. The method of claim 10 , wherein the determining is performed based on data read in a read operation of memory cells included in the unselected pages or according to a number of over-write operations performed in the selected page.

12. The method of claim 11 , wherein the read operation is performed on all the memory cells, a portion of the memory cells or memory cells programmed to the highest program status among the memory cells.

13. The method of claim 12 , wherein, the read operation is performed on all the memory cells for all program statuses that the memory cells are to have.

14. The method of claim 12 , wherein, the read operation is performed on a portion of the memory cells for partial program statuses that the memory cells are to have.

15. The method of claim 11 , wherein the read operation is performed using, as a read voltage, a voltage higher than a highest voltage of a selected threshold voltage distribution among threshold voltage distributions that memory cells included in the unselected pages are to have.

16. The method of claim 10 , wherein the skipping includes:

newly selecting a page different from the selected page; and

performing the over-write operation on the newly selected page.

17. The method of claim 11 , wherein the determining includes:

determining, when the number of over-write operations performed on the selected page is larger than or equal to a reference number, that there is the high probability of the program disturb in the unselected pages; and

determining when the number of over-write operations performed on the selected page is smaller than the reference number, that there is not the high probability of the program disturb in the unselected pages.

18. A method for operating a memory system, the method comprising:

performing rebooting after sudden power-off;

determining, in the rebooting, whether there is a high probability of a program disturb of unselected pages coupled to the same word line as a selected page according to a number of over-write operations performed on the selected page;

performing, when it is determined that there is not the high probability of the program disturb, the over-write operation on the selected page; and

newly selecting, when it is determined that there is the high probability of the program disturb, a page different from the selected page, and performing the over-write operation on the newly selected page.

19. The method of claim 18 , wherein the determining includes, when the number of over-write operations performed on the selected page is larger than or equal to a reference number, determining that there is the high probability of the program disturb in the unselected pages.

20. The method of claim 19 , wherein the determining includes, when the number of over-write operations performed on the selected page is smaller than a reference number, determining that there is not the high probability of the program disturb in the unselected pages.

21. A memory system comprising:

a memory device including a plurality of pages; and

a memory controller configured to control, when a write operation is interrupted to a first page among the pages due to a sudden power off, the memory device to perform an over-write operation to a second page,

wherein the second page has neighboring pages sharing a word line therewith and the neighboring pages have a low probability of a program disturb, and

wherein the memory controller selects a candidate page as the second page based on a result of a read operation to neighboring pages of the candidate page or based on a number of the over-write operations previously performed to the candidate page among the pages.