Memory system configured to estimate a read voltage using a histogram

A memory system comprising:

• a nonvolatile memory that includes a plurality of memory cells;
• and
• a memory controller configured to determine a read voltage to be applied to the nonvolatile memory to read first data encoded by a first encoding scheme of a plurality of error mitigation encoding schemes from the nonvolatile memory, by generating a first histogram indicating the number of memory cells for each of a plurality of threshold voltage ranges, and then estimating the read voltage used for reading the first data by using:
• (a) the first histogram after correction which is obtained by correcting the first histogram based on a parameter of the first encoding scheme and a parameter of a second encoding scheme of the plurality of error mitigation encoding schemes, and an estimation function for estimating a read voltage used for reading second data encoded by the second encoding scheme,
• (b) the first histogram before correction, and the estimation function after correction which is obtained by correcting the estimation function based on the parameter of the first encoding scheme and the parameter of the second encoding scheme, or
• (c) the first histogram after correction which is obtained by correcting a part of the first histogram based on the parameter of the first encoding scheme and the parameter of the second encoding scheme, and the estimation function after correction which is obtained by correcting a part of the estimation function based on the parameter of the first encoding scheme and the parameter of the second encoding scheme.