| 摘要 |
PURPOSE:To perform a due processing operation with use of the highly reliable data by checking the coincidence between the data written in the 1st and 2nd specific addresses through the comparison of them to decide whether the data are destroyed or not and therefore inhibiting the use of the destroyed data to carry on the processing to minimize the damage. CONSTITUTION:In an execution mode of a navigation mode, the same data are written in two specific addresses before and after the data on an EEPROM 25 are updated. These written data are compared with each other and the coincidence of them is checked at initialization. Thus it is possible to decide whether a power supply is turned off and the data are destroyed or not when the data on the EEPROM 25 are updated. As a result, the destroyed data are never used when a due processing operation is carried on. Then the processing can be carried out with use of the highly reliable data. |
