Memory devices with improved refreshing operations
A method and a system for memory cell programming and erasing with refreshing operation are disclosed. The system includes a selecting module, a processing module and a refresh module. In the method, at first, a target memory cell from a plurality of memory cells in a memory device is selected. Thereafter, the target memory cell belonging to a line of the matrix is programmed or erased by applying a selecting voltage on the target memory cell and a location-related memory cell belonging to the line of the matrix. Then, a refreshing operation to refresh the location-related cell is performed.
1. A method, comprising:
selecting a target memory cell from a plurality of memory cells of a matrix in a memory device;
programming or erasing the target memory cell belonging to a line of the matrix by applying a selecting voltage to the target memory cell and a first location-related cell belonging to the line of the matrix;
performing a first refreshing operation to refresh the first location-related memory cell; and
performing a second refreshing operation to refresh all of second location-related memory cells remaining in the line of the matrix except the target memory cell and the first location-related memory cell by performing a plurality of sub-refreshing operations, each of the plurality of sub-refreshing operations comprising:
reading data stored in one of the second location-related memory cells; and
writing the data back to the one of the second location-related memory cells.
2. The method of claim 1 , wherein the first refreshing operation comprises:
reading data stored in the first location-related memory cell; and
writing the data back to the first location-related memory cell.
3. The method of claim 2 , wherein the first refreshing operation comprises:
determining if a voltage level of the first location-related memory cell is lower than a predetermined verifying voltage level; and
rewriting the data back to the first location-related memory cell when the voltage level is higher than or equal to the predetermined verifying voltage level.
4. The method of claim 2 , wherein the first refreshing operation further comprises:
determining if a current level of the first location-related memory cell is lower than a predetermined verifying current level; and
rewriting the data back to the first location-related memory cell when the current level is higher than or equal to the predetermined verifying current level.
5. The method of claim 2 , wherein the first refreshing operation further comprises:
determining if a voltage level of the first location-related memory cell is higher than a predetermined verifying voltage level; and
rewriting the data back to the first location-related memory cell when the voltage level is lower than or equal to the predetermined verifying voltage level.
6. The method of claim 2 , wherein the first refreshing operation further comprises:
determining if a current level of the first location-related memory cell is higher than a predetermined verifying current level; and
rewriting the data back to the first location-related memory cell when the current level is lower than or equal to the predetermined verifying current level.
7. The method of claim 1 , wherein each of the plurality of sub-refreshing operations further comprises:
determining if a voltage level of the one of the second location-related memory cells is lower than a predetermined verifying voltage level; and
rewriting the data back to the one of the second location-related memory cells when the voltage level is higher than or equal to the predetermined verifying voltage level.
8. The method of claim 1 , wherein each of the plurality of sub-refreshing operations further comprises:
determining if a current level of the one of the second location-related memory cells is lower than a predetermined verifying current level; and
rewriting the data back to the one of the second location-related memory cells when the current level is higher than or equal to the predetermined verifying current level.
9. The method of claim 1 , wherein each of the plurality of sub-refreshing operations further comprises:
determining if a voltage level of the one of the second location-related memory cells is higher than a predetermined verifying voltage level; and
rewriting the data back to the one of the second location-related memory cells when the voltage level is lower than or equal to the predetermined verifying voltage level.
10. The method of claim 1 , wherein each of the plurality of sub-refreshing operations further comprises:
determining if a current level of the one of the second location-related memory cells is higher than a predetermined verifying current level; and
rewriting the data back to the one of the second location-related memory cells when the current level is lower than or equal to the predetermined verifying current level.
11. A system, comprising:
a selecting module configured to select a target memory cell from a plurality of memory cells arrange in a matrix in a memory device;
a processing module configured to program or erase the target memory cell belonging to a line of the matrix, the operation for programming or erasing the target memory cell including applying a selecting voltage to the target memory cell and call location-related memory cells belonging to the line of the matrix, wherein the location-related memory cells comprises a first location-related memory cell and a plurality of second location-related memory cells, and the second location-related memory cells are cells remaining in the line of the matrix except the target memory cell and the first location-related memory cell; and
a refresh module configured to perform a first refreshing operation to refresh the first location-related memory cell and to perform a second refreshing operation to refresh all of the second location-related memory cells by performing a plurality of sub-refreshing operations, each of the plurality of sub-refreshing operations comprising:
reading data stored in one of the second location-related memory cells; and
writing the data back to the one of the second location-related memory cells.
12. The system of claim 11 , wherein the refresh module is further configured to perform:
determining if a voltage level of the location-related memory cell is lower than a predetermined verifying voltage level; and
rewriting the data back to the location-related memory cell when the voltage level is higher than or equal to the predetermined verifying voltage level.
13. The system of claim 11 , wherein the refresh module is further configured to perform:
determining if a current level of the location-related memory cell is lower than a predetermined verifying current level; and
rewriting the data back to the location-related memory cell when the current level is higher than or equal to the predetermined verifying current level.
14. The system of claim 11 , wherein the refresh module is further configured to perform:
determining if a voltage level of the location-related memory cell is higher than a predetermined verifying voltage level; and
rewriting the data back to the location-related memory cell when the voltage level is lower than or equal to the predetermined verifying voltage level.
15. The system of claim 11 , wherein the refresh module is further configured to perform:
determining if a current level of the location-related memory cell is higher than a predetermined verifying current level; and
rewriting the data back to the location-related memory cell when the current level is lower than or equal to the predetermined verifying current level.
16. The system of claim 11 , wherein the plurality of memory cells are located at respective intersections of the plurality of bit lines and the plurality of word lines.
17. The system of claim 16 , wherein the plurality of memory cells in the line are electrically connected through one of the plurality of word lines of the memory device.
18. The system of claim 16 , wherein the plurality of memory cells in the line are electrically connected through one of the plurality of bit lines of the memory device.
19. A computer program product that includes a non-transitory computer-readable medium, the medium having stored thereon instructions which, when executed by a processor, causes the processor to execute:
selecting a target memory cell from a plurality of memory cells of a matrix in a memory device;
programming or erasing the target memory cell belonging to a line of the matrix by applying a selecting voltage to the target memory cell and a first location-related cell belonging to the line of the matrix;
performing a first refreshing operation to refresh the first location-related memory cell; and
performing a second refreshing operation to refresh all of second location-related memory cells remaining in the line of the matrix except the target memory cell and the first location-related memory cell by performing a plurality of sub-refreshing operations, each of the plurality of sub-refreshing operations comprising:
reading data stored in one of the second location-related memory cells; and
writing the data back to the one of the second location-related memory cells.
20. The system of claim 11 , wherein the first refreshing operation comprises:
reading data stored in the first location-related memory cell; and
writing the data back to the first location-related memory cell.