| 摘要 |
PROBLEM TO BE SOLVED: To accurately judge the destruction of memory content using decision by a majority. SOLUTION: A RAM is provided with four memory areas 0 to 3. The same data are successively recorded in the four memory areas. Write progress situation information showing that each area is in the middle of being written in also recorded. When a runaway of a CPU takes place, rest processing is performed. In such a case, memory content is restored by decision by a majority using the data of the areas 0 to 3. However, decision by a majority which uses the stored data of the memory areas is performed while excluding memory areas in the middle of being written on the basis of the write progress situation information. The data are desirably offset among areas when the data are recorded in the areas 0 to 3. At the time of recovery processing, offset is corrected and subsequently decision by a majority processing is performed. Even in case a situation in which all the memory is painted out with the same value takes place, it is possible to decide memory content destruction. |
