MEMORY CONTROLLER, FLASH MEMORY SYSTEM, AND STORAGE CONTROL METHOD

PROBLEM TO BE SOLVED: To early recognize a defective block regardless of whether a flash memory is reliable or not.SOLUTION: In a memory controller, a plurality of physical blocks are assigned to a logical block as a positive physical block and sub-physical block. The memory controller specifies the positive physical block and sub-physical block corresponding to a write destination logical block; writes write object data to each of those blocks and reads the write object data from those blocks; and determines whether or not there is an error in each of a plurality of write object data items that have been read. If write object data having an error is found, the memory controller manages a physical block including a physical page of the write object data having the error as a defective block.