| 摘要 |
PURPOSE:To detect the runaway of a program without reducing the amount of information of an operand even when there if no problem of a specified address. CONSTITUTION:If the program runs away, it is possible that status signals S1 and S2 become '1' and '0' during an object code fetch or that the status signals S1 and S2 both become '1' during an operand fetch. It is considered that a malfunction mentioned above occurs when an object code read out of an address #4 by a processor 1 is judged as a 2-bit instruction although it is a 5-bit instruction actually because the storage contents of the address #4 are destroyed. Then output signals (c) and (d) of a check circuit 6 become '1' if the runaway mentioned above occurs, so those signals (c) and (d) are utilized as the reset input or interruption level input of the processor 1 to prevent the program from being run away. |
