Memory system

A memory system comprising:

• a first nonvolatile memory for storing first data and a first error correction code generated from the first data;
• a second nonvolatile memory for storing a second error correction code generated from the first data and the first error correction code;
• a first error correction unit configured to execute error correction processing on the first data by using the first error correction code stored in the first nonvolatile memory;
• a second error correction unit configured to execute error correction processing on the first data by using the second error correction code stored in the second nonvolatile memory;
• and
• an interface configured to transmit the first data after the error correction to a host.

A method of error correction processing in a memory system having a first nonvolatile memory for storing first data and a first error correction code generated from the first data, and a second nonvolatile memory for storing a second error correction code generated from the first data and the first error correction code, said method comprising:

• receiving a request for the first data;
• reading the first data from the first nonvolatile memory and detecting an error in the first data;
• performing error correction processing on the first data using the first error correction code stored in the first nonvolatile memory;
• determining whether or not the error correction processing is successful;
• if the error correction processing is successful, transmitting the first data after the error correction to a requestor of the first data;
• and
• if the error correction processing is not successful, performing another error correction processing on the first data using the second error correction code stored in the second nonvolatile memory.