Memory system and method for controlling the same

A memory system, comprising:

• a nonvolatile memory including a plurality of physical blocks;
• and
• a controller configured to control reading and writing of the nonvolatile memory, the controller being further configured to:
• set a plurality of logical blocks, each including physical blocks;
• manage a first table including, for each logical block, a first value indicating a threshold voltage to be used for reading data from the logical block;
• manage a second table including, for each physical block having a corrected threshold voltage that is statistically determined to be an outlier from among corrected threshold voltages for each physical block, a second value indicating the corrected threshold voltage for the physical block together with an identifier of the physical block;
• perform a threshold voltage tracking for identifying a threshold voltage suitable for reading data from a first physical block if a reading of data from a first logical block including the first physical block fails, and then retry the reading of the data from the first logical block using the threshold voltage obtained by the threshold voltage tracking;
• update a threshold voltage for the first logical block including the first physical block in the first table to the threshold voltage obtained by the threshold voltage tracking if an identifier of the first physical block is not recorded in the second table;
• and
• prohibit updating of the threshold voltage for the first logical block in the first table to the threshold voltage obtained by the threshold voltage tracking if the identifier of the first physical block is recorded in the second table.