Memory system

1. A memory system, comprising:

a non-volatile memory including a plurality of groups, each of the plurality of groups including a plurality of cell units, each of the plurality of cell units including a plurality of memory cells; and

a memory controller configured to control the non-volatile memory, wherein

the memory controller is configured to execute a first operation, the first operation including:

based on a first correction amount associated with a target group, reading data from the target group;

executing error correction on the read data;

calculating a second correction amount based on the read data and the read data after the error correction; and

updating the first correction amount to the second correction amount,

the memory controller is configured to select a first group of the plurality of groups as the target group, and

in response to a read request specifying a logical address corresponding to a first cell unit included in the first group, the memory controller is further configured to

read data from the first cell unit based on the first correction amount,

execute the error correction on the read data from the first cell unit, and

calculate the second correction amount based on the read data from the first cell unit and the read data from the first cell unit after the error correction.

2. The memory system according to claim 1 , wherein in response to a read request specifying a logical address corresponding to a second cell unit included in the first group, the second cell unit being different from the first cell unit, the memory controller is further configured to;

calculate a third correction amount based on the first correction amount,

read data from the second cell unit based on the calculated third correction amount,

execute the error correction on the read data from the second cell unit,

calculate a fourth correction amount based on the read data from the second cell unit and the read data from the second cell unit after the error correction, and

calculate the second correction amount based on the fourth correction amount.

3. The memory system according to claim 1 , wherein the memory controller is further configured to select a second group as the target group after performing the first operation related to the first group when a condition is satisfied.

4. The memory system according to claim 3 , wherein the condition includes a number of requests received from a host device being equal to or greater than a first threshold.

5. The memory system according to claim 3 , wherein the condition includes the memory system starting to transition from a first state to a second state.

6. The memory system according to claim 5 , wherein:

the first state is an active state; and

the second state is a standby state.

7. The memory system according to claim 5 , wherein:

the first state is an active state; and

the second state is a power-off state.

8. The memory system according to claim 3 ,

wherein satisfying the condition includes satisfying a first condition or a second condition, and

wherein the memory controller is further configured to:

in a case where the first condition is satisfied when the first group is selected as the target group, select the second group as the target group after performing the first operation related to the first group, and

in a case where the second condition is satisfied when a third group is selected as the target group, select a fourth group as the target group after performing the first operation related to the third group.

9. The memory system according to claim 8 , wherein when a number of times the first operation related to the first group is executed is equal to or greater than a second threshold, the memory controller is further configured to change a condition for executing the first operation related to the first group from the first condition to the second condition.

10. The memory system according to claim 8 , wherein:

the first condition includes the memory system starting to transition from a first state to a second state; and

the second condition includes the memory system starting to transition from the first state to a third state.

11. The memory system according to claim 10 , wherein:

the first state is an active state;

the second state is a first standby state; and

the third state is a second standby state in which a frequency of occurrence is lower than that in the first standby state.

12. The memory system according to claim 11 , wherein when a number of times the first operation related to the first group is executed is equal to or greater than a second threshold, the memory controller is further configured to change a condition for executing the first operation related to the first group from the first condition to the second condition.

13. The memory system according to claim 1 , wherein each of the plurality of groups is a unit for erasing data.

14. The memory system according to claim 13 , wherein each of the plurality of cell units is a unit for writing data.

15. The memory system according to claim 14 , wherein the plurality of memory cells in a single cell unit among the plurality of cell units are commonly connected to a same word line, and respectively connected to different bit lines.

16. A memory system, comprising:

a non-volatile memory including a plurality of groups, each of the plurality of groups including a plurality of cell units, each of the plurality of cell units including a plurality of memory cells; and

a memory controller configured to control the non-volatile memory, wherein

the memory controller is configured to execute a first operation, the first operation including:

based on a first correction amount associated with a target group, reading data from the target group;

executing error correction on the read data;

calculating a second correction amount based on the read data and the read data after the error correction; and

updating the first correction amount to the second correction amount,

the memory controller is configured to select a first group of the plurality of groups as the target group,

the memory controller is further configured to select a second group as the target group after performing the first operation related to the first group when a condition is satisfied, and

the condition includes a number of requests received from a host device being equal to or greater than a first threshold.