| 摘要 |
PURPOSE:To detect the fact that the content of data changes widely from a specification value by malfunction by monitoring the temporal change of the content of the data at a cycle earlier than that at which the data changes. CONSTITUTION:The data converted to parallel binary codes by a Gray-binary conversion circuit 4 is sent to a second latch circuit 6 at the next timing of a clock signal 13. Furthermore, at the time of the next clock or between the clock and the next clock, the content of a first latch circuit 5 and that of the second latch circuit 6 are sent to a subtraction circuit 7 simultaneously, and the comparison and subtraction of two data are performed, and a subtraction result is checked by a limit check circuit 8. Thereby, in the case of detecting the fact that two or more numeric values are outputted as the result of subtraction at the limit check circuit 8, it shows that an error occurs in the data inputted to a buffer circuit 9 at a preceding timing, then, an abnormality alarm signal 10 is sent from the limit check circuit 8. |
