Memory system

A memory system which is connectable to a host, the memory system comprising:

• a non-volatile memory;
• a volatile memory;
• and
• a controller configured to cause the host to store data in a memory region within the host and cause the host to read the data from the memory region within the host,
• wherein the controller is configured to:
• store first data in the non-volatile memory, the first data indicating a relation between a logical address and a physical address;
• cause the host to read second data that is stored in the memory region as cache data and cause the host to store the second data in the memory region, the second data including at least a part of the first data stored in the non-volatile memory;
• and
• store third data in the volatile memory, the third data including information for managing the second data stored in the memory region, and
• wherein the controller includes:
• a first encoding/decoding circuit configured to execute encoding/decoding with a first encoding scheme;
• a second encoding/decoding circuit configured to execute encoding/decoding with a second encoding scheme having a higher error correcting capability than an error correcting capability of the first encoding scheme;
• and
• an encoding scheme selecting circuit configured to select one of the first encoding/decoding circuit and the second encoding/decoding circuit to perform encoding of the second data to be stored in the memory region, based on a decoding result of decoding read second data that has been read from the memory region within the host.