| 摘要 |
<p>PURPOSE:To detect accurately a start bit even when a noise pulse is mixed by detecting either a short or a long noise pulse before the start bit. CONSTITUTION:When the change of a data input from ''1'' to ''0'' after the reception of the stop bit of a serial data input is detected, it is brought once into the start bit detecting state. Then whether or not a short noise pulse is detected depending whether a data input restores to logical ''1'' or not during e.g., 2-clock cycle from the sampling clock at detection, and whether or not a long noise pulse is detected depending whether the majority of the sampling data is logical ''1'' or not by plural clocks after a prescribed time from the sampling clock detecting the change of data input from ''1'' to ''0''. When the noise pulse is detected, the state is restored again to the start bit detection standby state.</p> |
