| 摘要 |
PROBLEM TO BE SOLVED: To detect and properly repair an error occurring to the external storage device even in such a case by giving an identification number to each block of a memory card and handling an address error by using identification numbers. SOLUTION: For example, data divided from the head of a file are stored by blocks having logical addresses '1', '2', and '3' when the file is updated, and identification numbers '6', '4', and '1' are given to the respective blocks '1', '2', and '3'. When the data of the block having the logical address '2' is rewritten, the logical address '2' is assigned to another block, new data are written, and the value '5' obtained by increasing the identification number of the original block by one is set as its identification number. In this stage, the two blocks have the same address, but a final flag is stored in the block having the larger identification number by regarding the data stored in the block as new data and the original block is erased. |
