| 摘要 |
PROBLEM TO BE SOLVED: To detect the possibility that a momentary break was caused during data base update in the past by setting and releasing a given flag and recording and erasing a prescribed semaphore in a nonvolatile memory in a predetermined timing. SOLUTION: When a system is activated, a log-in process is performed (S01). At the log-in time, whether a flat is on or off is inspected (S02); when the flat is on, it is considered that a momentary break was caused at the last time use to restore the data base (S10), the flag is set on again (S03), and an update process for the data base is activated to increase the prescribed semaphore by one (S04). Then the data base is updated (S05), the semaphore is decreased by one (S06), and the update process is completed. Then the value of the semaphore is checked at the log-out time (S07); when the value of the semaphore is 0, it is decided that the process ends normally, the flag is set off (S08), and a log-out process is performed to finish the system use (S09).
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