| 摘要 |
PURPOSE:To make it unnecessary to set an initial value of a circuit to be diagnosed at starting the diagnosis, and also to apply it easily to a circuit to be diagnosed containing such a circuit as it is impossible to set the initial value by said result, by starting an operation of a diagnosing circuit in accordance with operation period information of the circuit to be diagnosed. CONSTITUTION:A diagnosis start signal 18 is held by a holding circuit 11, and also is inputted to a flip-flop circuit 12. On the other hand, various operation period information 16-1 of a circuit to be diagnosed 16 is selected, and in accordance with this information, a signal showing the longest operation period of the circuit to be diagnosed 16 is generated by a generating circuit 17. An output signal 12-1 is synchronized to the longest operation period of the circuit to be diagnosed 16, is converted to a signal of variation point information by a differentiating circuit 13, and is applied to a reference signal generating circuit 14 which generates a reference signal for diagnosing an output signal of the circuit to be diagnosed 16. As a result, the output signal of the reference signal generating circuit 14 is synchronized with the output signal of the circuit to be diagnosed 16, and diagnosis is started by a compare-diagnosing part 15, and is continued until a diagnosis end signal 20 is inputted. |
