MEMORY CONTROLLER, FLASH MEMORY SYSTEM EQUIPPED WITH MEMORY CONTROLLER, AND CONTROL METHOD OF FLASH MEMORY

PROBLEM TO BE SOLVED: To perform, only when a physical block (PB) in which data which is rarely rewritten exists, control of wear levelling including the PB. SOLUTION: A CTL updates the count value (CV) of a counter, on the basis of the assignment of a new logical block (LB) to the PB, and writes count information (CI) to be determined on the basis of the count value in the PB to which the new LB is assigned. The CTL determines, on the basis of the CV and the CI stored in the PB, whether or not to transfer data stored in the PB to another PB. When it is positively determined, the data stored in the PB are transferred to a free block which is detected by free block retrieval. But the CTL performs negative determination so as to perform no data transfer in a case where the times of deletion of the free block in a data transfer destination is less than prescribed reference times even when the positive determination is made (when the PB is determined to store the data which is rarely rewritten). COPYRIGHT: (C)2010,JPO&INPIT