Patent ID: 8732414

Claim:
A control device comprising: a storage device that includes a first storage area including a plurality of blocks into which data can be written more than once, each block stores a flag indicating whether or not the block is allowed to be used, and a second storage area into which data can be written only once; a creation unit configured to create, based on the flag stored in the blocks, a flag management information for managing whether or not data can be stored in the block of the storage device; a management information controller configured to store the flag management information in the second storage area; and a detection unit configured to detect a block that is not allowed to be used, wherein the management information controller determines, based on a detection result of the detection unit, that a number of blocks that are not allowed to be used is increased, and stores the flag management information reflecting the detection result of the detection unit in the second storage area when the determined number becomes greater than or equal to a predetermined value.