| 摘要 |
PURPOSE:To remove a signal having noise-like characteristics such as chattering by repeatedly cancelling edge detection of a signal to be detected during the continuation of a detecting signal state different from an ordinary detecting signal state for a prescribed period after detecting the edge of the signal to be detected. CONSTITUTION:At the time of generating an output from a discrepancy detecting circuit EX-OR for detecting a discrepancy between a stored signal precedently arriving at a flip flop FF-T and a current signal to be detected, the length of the signal coincident with the preceding arriving signal is measured by a counter CO2, the continuation of the signal state of an ordinary arriving signal for a prescribed time T after detecting the edge of the signal (b) to be detected is measured by a counter CO3 and the passage of a prescribed time T1 after the edge detection of the signal (b) is measured by a counter CO1. When a detecting signal state different from the ordinary detecting signal state is continued for a prescribed time, the edge detection of the signal (b) is repeatedly cancelled and the edge of the signal (b) to be detected is detected when a noise state such as chattering is removed. |
