| 摘要 |
PURPOSE:To make decision accurate by confirming writing and reading operation of a memory then advancing a program according to stored content of the memory. CONSTITUTION:When power failure is restored and a power source is made again and a microcomputer is reset, residual voltage of a capacitor is measured utilizing A/D converting function of the microcomputer 1. Voltage at the time of power source making is taken out by a conversion table and the value is compared with the lowest voltage of RAM holding. When the voltage is higher than the lowest voltage of RAM holding, the state of preservation of the RAM is reconfirmed by collation of codes. When all codes conform, it is decided that the state of preservation of the RAM is proper, and decided whether writing operation and reading operation are normal or not. The program is advanced according to the stored content of the memory only after confirming that the RAM operates normally.
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