Patent ID: 7996634

Claim:
A memory system comprising: a first nonvolatile memory to store user data; a second nonvolatile memory to store management data; and a controller to control read/write of data with respect to the first and second nonvolatile memories, the controller being configured to compare given management data to be written into the second nonvolatile memory with management data held by the second nonvolatile memory, configured to write the given management data into the second nonvolatile memory when the given management data is not the same as the management data held by the second nonvolatile memory, and configured to prevent the given management data from being written into the second nonvolatile memory when the given management data is the same as the management data held by the second nonvolatile memory, wherein: a reverse flag of one bit is allotted to write data of a plurality of bits, the reverse flag being indicative of reverse of the write data, and the reverse flag is used when the number of bits to be changed is larger than the number of bits not to be changed with respect to data to be written to the second nonvolatile memory.