| 摘要 |
PROBLEM TO BE SOLVED: To hold set data even during irregular power-off such as the time of battery replacement without using a battery by reading and storing backup application data from an optical disc when a CPU detects power-off, and storing set data on a flash ROM. SOLUTION: When an ACC(accessory) switch is switched off, a CPU 2 detects power-off and sets a flag of an SRAM 8 to '1' and stops a watchdog timer(WDT) handler. After a specified time, navigation is reset by a WDT. The CPU 2 then reads again an initial program load(IPL) recorded on a flash ROM 1 and confirms '1' of the flag of the SRAM 8. The CPU 2 develops backup application data stored in an optical disc in a DRAM and executes it to copy set stored data in the SRAM 8 on the DRAM 7. |
