Patent ID: 8286028
Filing Date: 2012-10-09
Classification: G06F,G11C

Abstract:
1. A backup method for making a backup of cache data stored in a volatile memory to a nonvolatile memory by using a controller, the backup method comprising: writing the cache data stored in the volatile memory in a selected area of the nonvolatile memory; generating parity data by calculating an exclusive OR of each of a plurality of predetermined parts of the cache data in the volatile memory; generating a plurality of cyclic redundancy check codes from each of the predetermined parts of the cache data in the volatile memory respectively; checking an error of each of the predetermined parts of the cache data in the nonvolatile memory by using the cyclic redundancy check codes; verifying whether an error found in a checked part of the cache data in the nonvolatile memory can be recovered by using the parity data; rewriting a part of the cache data when the error found in the part of the cache data in the nonvolatile memory cannot be recovered by using the parity data in an area of the nonvolatile memory different from the selected area; and writing the generated parity data into the nonvolatile memory.