| 摘要 |
PURPOSE: A page mapping method which supports safe file removal in a NAND-based block device and a recording medium thereof are provided to supply a page mapping method which supports the safe file removal, thereby safely removing a security file. CONSTITUTION: When an overwriting request for a logic page is existed, the number of overwriting requests for the logic page is counted (S503). When the number of overwriting requests exceeds a threshold value, a safe file removal function is performed in order not to restore original data stored in the logic data (S509). The number of overwriting requests, arrangement of the whole physical block having voided original data in the logic page, and the number of removal of a physical block including the voided original data are stored in a mapping table. [Reference numerals] (AA) Start; (BB,DD,FF) No; (CC,EE,GG) Yes; (HH) Finish; (S501) Is the overwriting of a logic page requested ?; (S507) Deletion number of E_b=block ?; (S509) Perform a block deletion operation
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