Storage device and operating method thereof
The present disclosure relates to an electronic device. A storage device includes a memory device configured to include a plurality of memory cells and a memory controller configured to determine a read voltage for a read operation to be performed on the memory device according to whether the read operation is a cache read operation.
1. A storage device, comprising:
a memory device configured to include a plurality of memory cells; and
a memory controller configured to determine a read voltage for a read operation to be performed on selected memory cells, among the plurality of memory cells, according to environments when the read operation is performed on the selected memory cells,
wherein the memory controller includes a management table that stores environment information representing the environments when the read operation is performed on the selected memory cells,
wherein the memory controller determines the read voltage based on the environment information,
wherein the memory controller includes a read voltage setting component determining at least one offset voltage according to the environment information and determining the read voltage by reflecting the at least one offset voltage into a default read voltage used in a normal read operation,
wherein the at least one offset voltage has different values depending on a type of the read operation, and
wherein the type of the read operation includes at least one of a cache read operation, a short-time read operation, a cross temperature read operation, and a first page read operation.
2. The storage device of claim 1 , wherein the read voltage setting component comprises:
the management table; and
a read voltage determiner configured to determine the at least one offset voltage on the basis of the type of the read operation and the environment information.
3. The storage device of claim 2 , wherein the read voltage determiner determines a first offset voltage as the at least one offset voltage when the read operation is the cache read operation.
4. The storage device of claim 3 , wherein the first offset voltage corresponds to increases in threshold voltages of the plurality of memory cells in the cache read operation in comparison with the normal read operation.
5. The storage device of claim 2 , wherein the read voltage determiner determines a second offset voltage as the at least one offset voltage when the read operation is the short-time read operation is to be performed before a predetermined reference time elapses after a program operation is performed on the selected memory cells.
6. The storage device of claim 5 , wherein the second offset voltage decreases according to a length of a time elapsed before the read operation is performed after the program operation is be performed.
7. The storage device of claim 2 , wherein the read voltage determiner determines a third offset voltage as the at least one offset voltage when the read operation is the cross temperature read operation where a difference in a temperature of the memory device between during the read operation and during a previous program operation performed on the selected memory cells is greater than a predetermined reference temperature.
8. The storage device of claim 7 , wherein the third offset voltage increases as the difference increases.
9. The storage device of claim 7 , wherein the third offset voltage has a value greater than 0 V when the temperature during the program operation is higher than the temperature during the read operation, and the third offset voltage has a value smaller than 0 V when the temperature during the program operation is lower than the temperature during the read operation.
10. The storage device of claim 2 , wherein the read voltage determiner determines a fourth offset voltage as the at least one offset voltage when the read operation is the first page read operation in which a memory block including the selected memory cells is an unselected block in a previous operation.
11. The storage device of claim 10 , wherein the fourth offset voltage has a positive voltage value greater than 0 V.
12. The storage device of claim 2 , wherein the read voltage setting component further comprises a read operation controller controlling the memory device to perform the read operation using the read voltage.
13. The storage device of claim 2 , wherein the management table stores the environment information including at least one of an erase count, a write count, a read count, a temperature during a program operation, information about a time taken to perform the program operation, and information as to whether or not a cache read operation is supported according to each of physical addresses corresponding to the plurality of memory cells.
14. The storage device of claim 2 , wherein the management table is managed in units of memory blocks, pages, or planes.