| 摘要 |
PURPOSE:To prevent malfunction or the like by setting up a checking data on a prescribed area of a memory, reading out the checking data during a processing cycle to check data and, when the data is destroyed, executing error processing. CONSTITUTION:The M0 digit of an M register in an RAM3 is specified by an ROM4 and the contents of the digit M0 are read out by a data destruction detecting circuit 11 to check whether the data are destroyed or not. At the destruction of data, a data destruction detection signal RES is outputted and sent to an ROM address part 5, which specifies the leading address of an all clear processing program of ROM4 to execute the all clear processing. Even if data are destroyed by the instantaneous change of power voltage, the status can be precisely detected and the error processing can be precisely attained. |
