Patent ID: 11886335
Assignee: KIOXIA CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 8:
9. A memory system comprising:
a nonvolatile memory including a plurality of blocks; and
a controller configured to perform a rewrite operation of rewriting data stored in each block including valid data to another block among the plurality of blocks, wherein
the controller is configured to:
manage a remaining time until a time point at which the rewrite operation is to be performed on each of the block including the valid data, the time point at which the rewrite operation is to be performed being a time point after a certain period has elapsed since the data is written to the block;
obtain i) a first number of blocks included in a first block set in which a remaining time, until the time point at which the rewrite operation is to be performed, is a first time and ii) a second number of blocks included in a second block set in which a remaining time, until the time point at which the rewrite operation is to be performed, is a second time longer than the first time, the first time and the second time being represented by multiples of a unit time;
calculate a first rewrite speed based on the first time and the first number of blocks;
calculate a second rewrite speed based on the second time and a sum of i) the first number of blocks and ii) the second number of blocks;
determine a maximum rewrite speed among the first rewrite speed and the second rewrite speed; and
perform, at the determined maximum rewrite speed, the rewrite operation on i) the first number of blocks included in the first block set and ii) the second number of blocks included in the second block set.