Patent ID: 8423709

Claim:
A controller, comprising: a first storing unit that stores therein page addresses indicating, in units of pages, physical storage positions within the storage area of a nonvolatile memory, and pieces of management information each indicating whether one or more special sectors, each being either a bad sector or a trimmed sector trimmed by a TRIM command, are present in a corresponding one of the pages, while a set of sector addresses each indicating a logical storage position within a storage area of the nonvolatile memory, a page address, and the pieces of management information are associated with each other; a first judging unit that, in a case where an access to a specified sector address has been requested, refers to a corresponding one of the pieces of management information and judges whether one or more special sectors are present in a page identified by the page address corresponding to the specified sector address; a generating unit that, in a case where one or more special sectors are present in the identified page, generates predetermined response data; and a controlling unit that, in a case where no special sector is present in the identified page, accesses the storage position in the nonvolatile memory that corresponds to the specified sector address.