| 摘要 |
PURPOSE:To shorten the time required for recurrence of multiframe synchronism by setting a prescribed count value to a counting means based on change information of the frame synchronous state, and starting the hunting operation for recurrence of multiframe synchronism simultaneously with settling of frame synchronism. CONSTITUTION:When the count value for division of multiframe is set to the counting means by a second control means in accordance with frame synchronizing information, which indicates that frame synchronism is settled, from a synchronism protecting means, a multiframe signal is outputted by the counting means. The synchronism disaccord state of multiframe is detected by a synchronism disaccord detecting means in accordance with this multiframe signal, and the timing of the counting operation of the counting means is shifted by a first control means in accordance with detection results. Thus, the prescribed count value is set to the counting means based on change information of the frame synchronous state in this manner to start the hunting operation for recurrence of multiframe synchronism simultaneously with settling of frame synchronism. |
