Abstract: A memory system includes a first nonvolatile memory, a second nonvolatile memory with a longer access latency than the first nonvolatile memory, a first error correction unit, a second error correction unit, and an interface. The first nonvolatile memory stores first data and a first error correction code generated for the first data. The second nonvolatile memory stores a second error correction code which is generated for the first data with a higher correction ability than that of the first error correction code. The first error correction unit performs error correction on the first data by using the first error correction code. The second error correction unit performs error correction on the first data by using the second error correction code. The interface transmits the first data after the error correction to a host.

Abstract: According to an embodiment, a semiconductor storage device includes a memory, an encoding unit that generates a parity, and a decoding unit that includes a syndrome calculating unit, an error position polynomial calculating unit, and an error searching and correcting unit, and performs an error correcting process based on data and the parity read from the memory. At the time of performing a compaction process, a process of the error searching and correcting unit is not performed, when the number of error bits acquired by an error position polynomial is equal to or less than a first threshold value based on valid data.