| 摘要 |
<p>A frame synchronization circuit allows the user to set up a backward protection stage count and a forward protection stage count to arbitrary values. The frame synchronization circuit has a frame synchronization pattern detecting circuit for detecting a frame synchronization pattern from received frame data and outputting a frame synchronization pattern detection signal, a frame synchronization state transition managing circuit for managing frame synchronization state transitions, and a frame timing generating circuit for detecting a transition from a hunting state managed by the frame synchronization state transition managing circuit and generating an enable signal. The frame synchronization state transition managing circuit manages the number of times that the frame synchronization pattern is detected and the number of times that the frame synchronization pattern is not detected, based on the enable signal and the frame synchronization pattern detection signal, makes a transition from the hunting state to a synchronization state if the frame synchronization pattern is detected consecutively for the backward protection stage count which is set up arbitrarily, and makes a transition from the synchronization state to the hunting state if the frame synchronization pattern is not detected consecutively for the forward protection stage count which is set up arbitrarily. <IMAGE></p> |
