| 摘要 |
PURPOSE:To prevent a power supply from being instantaneously interrupted or influenced by a line noise by judging a data error obtained before the generation of abnormality in a RAM based upon a check sum after removing the abnormality and specifying a restarting method in accordance with the presence of a data error. CONSTITUTION:At the time of a normal operation, the current execution address data of a specified program or current data in a CPU 2a-1 are stored in the operation status storing area of a RAM 2a-2 at every completion of one executed instruction, the check sum of data or the like is generated in accordance with the operating status and stored in a check sum storing area. When the CPU 2a-1 is reset due to instantaneous interruption or an external noise, the CPU 2a-1 stops operating. When the rest is released, the CPU 2a-1 judges errors in various data stored in the RAM 2a-2 based upon the check sum, and when there is no error, restarts the program from the operation status obtained before the generation of abnormality and stored in the RAM 2-2. At the time of detecting an error, the CPU 2a-1 clears the RAM 2a-2 and starts the program from an initial state. |
