| 摘要 |
<p>PURPOSE:To reproduce quickly a correct synchronizing signal by providing two synchronizing states for supply of synchronizing signals and switching these synchronizing states according to the situation. CONSTITUTION:A detection synchronizing signal given from a synchronizing detection circuit 21 is applied to a window coincidence detecting circuit 22. In the coincidence mode, a counter circuit 60 using a bit clock as an input is reset by the output of a reset switching circuit 50 and delivers synchronizing signals continuously. This means the 1st synchronizing state. This state is switched to the 2nd synchronizing state where the circuit 60 delivers a synchronizing signal if a detected synchronizing signal has a start-stop shift and no coincidence is detected by the circuit 22 by a loss. When the coincidence is continuously obtained in the prescribed times between the detected synchronizing signal and the synchronizing signal in the 2nd synchronizing state, there is switched to the 1st synchronizing state. Thus a correct synchronizing signal can be quickly reproduced.</p> |
