| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to store data without using a cell of large capacity in a navigation device provided with a function capable of writing data in a backup memory even when a battery is detached from the device. SOLUTION: A flash memory 24 is used as a backup memory. Thereby the necessity of power supply for storing data can be eliminated. An arithmetic processing unit(APU) 20 executes data writing in the flash memory 24 through a bus line 25, and in the case of writing data when a battery 1 is detached, power supply to external equipment such as an external data reader 30 and a communication equipment 40 is stopped and the external equipment side of the bus line 25 is set up to high impedance. Consequently current consumption required for writing data by power supply from a cell 12 can be reduced.</p> |
