Patent ID: 8443133
Filing Date: 2013-05-14
Classification: G06F,G11C

Abstract:
1. A memory system storing management information comprising: a nonvolatile memory including a plurality of memory cells, each one of the plurality of memory cells being capable of storing multiple bits; a volatile memory being capable of storing at least one part of management information including storage positions of data stored in the nonvolatile memory; and a memory controller configured to perform data management in the nonvolatile memory based on the management information stored in the volatile memory, wherein the memory controller includes: a management-information writing unit configured to update the management information stored in the volatile memory when the storage positions of data stored in the nonvolatile memory have been changed; a management-information storing unit configured to store a log indicating difference information before and after updating the management information in the nonvolatile memory, the log including a first log and a second log, the first log is created before updating the management information and the second log is created after updating the management information, and to store, when a predetermined condition is satisfied, the management information in the nonvolatile memory as a snapshot; and a management-information restoring unit configured to restore the management information on the volatile memory based on at least one of the snapshot and the log stored in the nonvolatile memory, wherein when an error has occurred in the memory system, the management-information restoring unit is configured to store, after restoring the management information based on a first snapshot and the log, restored management information as a second snapshot in the nonvolatile memory.