| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently update the storage data without increasing an erasure time and the number of erasure times by extracting only effective data record to transfer to a different block which is in an empty state and physically eliminating the block of a transfer destination to make it empty. SOLUTION: Various data are stored in a record unit of a different content in a data area 21, and header information that consists of the leading address position and record length of data record is stored in a header area 22. A block managing part 15 extracts the latest data record in each same content series from a block B1, e.g. when empty capacity of the block B1 becomes small and there is no room to additionally write the next data record and copies it to a block B2. In such cases, the header information is newly reproduced and written in the header area. With this, only effective data record is transferred to the block B2. After that, a storage area of the original block B1 is released due to physical erasure.</p> |
