| 摘要 |
PURPOSE:To checks the advance of a sequence all the time by an address comparison and to detect a fault immediately, by comparing the output of an address storage device with that of a comparison address storage device which generates expected addresses successively according to the progress of a program. CONSTITUTION:A microprocessor MPU outputs a storage address of a control memory CS to a comparing circuit CMP. Prior to the start of operation, addresses of the program of the microprocessor MPU are written in a buffer memory BF in specific order. The addresses of this memory BF are read by a clock RCK and compared with a program address MPA by the circuit CMP when the comparison address is generated. The comparison output of this circuit CMP is applied to a logical circuit together with a comparison enabling signal and when the comparison result shows coincidence, an FF is set. Thus, the advance of the sequence is checked all the time to detect a fault immediately. |
