Controller for controlling nonvolatile memory unit

A memory system comprising:

• a nonvolatile memory unit formed of at least one nonvolatile memory and storing management information for the nonvolatile memory unit;
• and
• a controller configured to control the nonvolatile memory unit, the controller including:
• means for writing, after writing of data into the nonvolatile memory unit, new management information that reflects the writing of data, into an area of the nonvolatile memory unit other than an area of the nonvolatile memory unit which stores last management information;
• means for writing, after the management information writing by the management information writing means, an old management information flag indicating that management information written by the management information writing means is old management information, in relation to the last management information stored in the nonvolatile memory unit;
• means for searching the nonvolatile memory unit for normal updated management information when the nonvolatile memory unit is initialized;
• and
• means for restoring updated management information based on normal old management information related to the old management information flag, if the search means does not find the updated, normal management information.

A method of controlling a nonvolatile memory unit formed of a plurality of physical blocks and configured to store management information for the nonvolatile memory unit, comprising:

• responding to a request for writing data into the nonvolatile memory unit, thereby writing the data into the nonvolatile memory unit;
• writing, after writing of data into the nonvolatile memory unit, new management information that reflects the writing of data, into an area of the nonvolatile memory unit other than an area of the nonvolatile memory unit which stores last management information;
• writing, after writing the new management information, an old management information flag indicating that the last management information is old management information, in relation to the last management information stored in the nonvolatile memory unit;
• searching the nonvolatile memory unit for updated, normal management information when initializing the nonvolatile memory unit;
• and
• restoring updated management information on the basis of normal, old management information related to the old management information flag, if the updated, normal management information is not found.