FRAME SYNCHRONIZING CIRCUIT

摘要

PURPOSE:To quicken the synchronizing restoration time in addition to the conventional synchronizing protection function by using a sequential filter to constitute a frame synchronizing circuit. CONSTITUTION:A frame synchronizing pattern is detected from an input signal by a pattern detector 13. A pseudo synchronizing pattern being a noise component is eliminated by a sequential filter 18 passing a frame period component fF of the synchronizing pattern only to extract the frame period component fF in an input signal and the component applies phase control to a frame counter 16. The frame counter 16 applies a synchronizing retrieval control by using the frame period component fF.