TRANSMISSION DATA FRAME SYNCHRONIZATION METHOD AND TRANSMISSION DATA FRAME SYNCHRONIZATION CIRCUIT

摘要

A transmission data frame synchronization circuit includes a SYNC detection unit for holding the position of the synchronous bit SYNC for each frame, a backward protection stage count processing unit for counting the number of frames in which a synchronous bit is detected during a non-synchronization period and outputting a synchronization confirmation pulse when a predetermined value is reached, and a forward protection stage count processing unit for counting the number of frames in which the position of a synchronous bit during a synchronization period does not match with the position in a frame preceding by one and outputting a non-synchronization confirmation pulse when a predetermined value is reached. Furthermore, the forward protection stage count processing unit clears the counting value when the position of the synchronous bit matches with the position in a frame preceding by one after a pseudo-synchronization state has occurred during synchronization.