Memory system
According to one embodiment, a memory system comprises a non-volatile semiconductor memory, a memory and a controller. The memory stores a management table including a plurality of parameters for managing the non-volatile semiconductor memory. The controller is configured to control the operation of the non-volatile semiconductor memory based on a first value of the parameters contained in the management table. The controller obtains a second value corresponding to the parameters from an operation log of the non-volatile semiconductor memory, compares the second value of the parameters with the first value, calculates the difference between the second value of the parameters and the first value when they are different from each other, calculates a correction value for correcting the first value when the difference is greater than a third value, and updates the first value of the management table based on the correction value.
1. A memory system comprising:
a non-volatile semiconductor memory;
a first memory configured to store an operation log obtained through an operation of the non-volatile semiconductor memory, the operation log including a plurality of parameters;
a second memory configured to store a management table including a plurality of parameter sets, each of the plurality of parameter sets including a plurality of parameters for managing the non-volatile semiconductor memory; and
a controller configured to control the operation of the non-volatile semiconductor memory on the basis of a parameter of the plurality of parameters included in each of the plurality of parameter sets,
wherein the controller obtains a first parameter from a first parameter set and a second parameter from the operation log, the second parameter having a same attribute as the first parameter, and
the controller calculates a difference between a value of the first parameter and a value of the second parameter, obtains a correction value when the difference is greater than a first threshold, and updates at least one parameter having a different attribute from the attribute of the first parameter in the first parameter set on the basis of the correction value.
2. The system according to claim 1 , wherein the controller obtains the correction value by calculation.
3. The system according to claim 1 , wherein the controller includes a plurality of tables each including a correction value, each of the correction value included in the plurality of tables differing mutually, selects one of the tables on the basis of the difference, and updates the at least one parameter in the first parameter set on the basis of a correction value included in the selected table.
4. The system according to claim 1 , wherein the first parameter and the second parameter are one of a number of writes of the non-volatile semiconductor memory, a temperature of the non-volatile semiconductor memory, and an access frequency of the non-volatile semiconductor memory.
5. The system according to claim 1 , wherein the non-volatile semiconductor memory includes the first memory.
6. The system according to claim 1 , wherein each of the plurality of parameter sets includes a parameter for an operation setting and a parameter for an operation environment.
7. The system according to claim 1 , wherein the parameter to be updated is an operation voltage.
8. A memory system comprising:
a plurality of non-volatile semiconductor memories;
a first memory configured to store an operation log obtained through an operation of each non-volatile semiconductor memory, the operation log including a plurality of parameters;
a second memory configured to store a management table including a plurality of parameter sets, each of the plurality of parameter sets including a plurality of parameters for managing each non-volatile semiconductor memory; and
a controller configured to control the operation of each non-volatile semiconductor memory on the basis of a parameter of the plurality of parameters included in each of the plurality of parameter sets,
wherein the controller obtains a first parameter from a first parameter set for each non-volatile semiconductor memory and a second parameter from the operation log of each non-volatile semiconductor memory, the second parameter having a same attribute as the first parameter, and
the controller calculates a difference between a value of each first parameter and a value of each second parameter, obtains a correction value for each non-volatile semiconductor memory when the difference is greater than a first threshold, determines priorities by comparing each correction value, and
updates at least one parameter having a different attribute from the attribute of the first parameter in the first parameter set of the high-priority non-volatile semiconductor memory, on the basis of the correction value.
9. The system according to claim 8 , wherein the controller obtains the correction value by calculation.
10. The system according to claim 8 , wherein the controller includes a plurality of tables each including a correction value, each of the correction value included in the plurality of tables differing mutually, selects one of the tables on the basis of the difference, and updates the at least one parameter in the first parameter set on the basis of a correction value included in the selected table.
11. The system according to claim 8 , wherein the first parameter and the second parameter are one of a number of writes of each non-volatile semiconductor memory, a temperature of each non-volatile semiconductor memory, and an access frequency of each non-volatile semiconductor memory.
12. The system according to claim 8 , wherein each non-volatile semiconductor memory includes the first memory.
13. The system according to claim 8 , wherein each of the plurality of parameter sets includes a parameter for an operation setting and a parameter for an operation environment.
14. The system according to claim 8 , wherein the parameter to be updated is an operation voltage.
15. A memory system comprising;
a non-volatile semiconductor memory;
a memory configured to store an operation log obtained through an operation of the non-volatile semiconductor memory; and
a controller configured to control the non-volatile semiconductor memory on the basis of a first parameter and a second parameter, both the first and second parameters included in a management table, wherein
the controller updates the first parameter, on the basis of the second parameter included in the management table and a third parameter included in the operation log, the second parameter having a same attribute as the third parameter and the first parameter having a different attribute from the attribute of the second parameter.
16. The system according to claim 15 , wherein the controller obtains a correction value for updating the first parameter by calculation on the basis of the second parameter and the third parameter.
17. The system according to claim 15 , wherein the controller includes a plurality of tables each including a correction value, each of the correction value included in the plurality of tables differing mutually, selects one of the tables on the basis of the second parameter and the third parameter, and updates the first parameter of the management table on the basis of a correction value included in the selected table.
18. The system according to claim 15 , wherein the second parameter and the third parameter are one of a number of writes of the non-volatile semiconductor memory, a temperature of the non-volatile semiconductor memory and an access frequency of the non-volatile semiconductor memory.
19. The system according to claim 15 , wherein the non-volatile semiconductor memory includes the memory.
20. The system according to claim 15 , wherein the first parameter is a parameter for an operation setting and the second parameter is a parameter for an operation environment.
21. The system according to claim 15 , wherein the first parameter is an operation voltage.