| 摘要 |
PROBLEM TO BE SOLVED: To guarantee the reliability of data which is read from a non-volatile memory after the lowering of a power source voltage and power interruption even when they occur by copying data management information stored in the non-volatile memory in a volatile memory before the usage of the non-volatile memory is started. SOLUTION: When a power source is turned on, the contents of a physical block flag group which constitutes data management information preserved inside a user data memory (flash memory) 200 and the contents of block mapping information are copied in a work memory 400 as a pre-processing for the usage start of the user data memory 200 and they are stored as the initial value of the physical block state flag group for displaying a latest state and as the initial value of block mapping information for display the latest state. At this time, one more group is copied and preserved in the work memory 400 concerning the contents of the physical block state flag group and stored as the physical block state flag group for display an initial state. |
