| 摘要 |
PURPOSE:To detect the abnormal termination of a software instruction due to the malfunction or the like of hardware by counting the number of steps of a microprogram to check whether the sequence is normal or not. CONSTITUTION:When a software instruction is stored in a software instruction register 1 and is executed, address information 3 is selected as an address of a microprogram storage means 5 in the first step of the instruction by a selector 14. Next, the program is read out to a register 6 by an update signal 15 outputted from a sequence control part 9 and is executed. Each time the program is executed, contents of a step counter 7 are counted up by a count signal 17. In the last step of the instruction, a check signal 20 is outputted to check the value of the step counter 7 and the value of a step register 23 in a comparator 21 by comparison; and if they are not ''0'', a sequence error signal 22 is generated to report the error to a processor. |
