| 摘要 |
PURPOSE: To detect a wisker-like abnormal pulse that is mixed into a clock signal without using a monitor clock signal. CONSTITUTION: A monostable multivibrator 1 inputs a clock signal CK of a cycle t1 and generates a pulse of a fixed time t2 (t1/t2<t2<t1) at the rise of an input signal. An inverting circuit 2 inputs the signal CK and outputs an inverted signal, and an asynchronous clear counter 3 starts a counting action at the rise of the output signal of the circuit 2 and is cleared at the fall of the pulse generated by the multivibrator 1. Then the output signal of the 2<1> digit of the counter 3 is defined as a clock abnormality detection signal AL. A monostable multivibrator 4 generates a pulse having a certain degree of pulse width at the rise of the signal AL and holds this signal AL as a detection result. |
