说明：  SDH是现代光纤通信中广泛应用的数据传输格式,在SDH帧结构中，前9列为开销字节，它包含了很多重要的信息，本程序为SDH开销的接收处理，查找帧头，分频，勤务话字节E1异步fifo。可拆为三段源代码，不知道能不能抵三个程序
(SDH is a modern optical fiber communication is widely used in data transmission format, in the SDH frame structure, as the former 9 overhead bytes, it contains a lot of important information, the procedures for receiving SDH overhead processing, search header, sub-frequency ,勤務if E1 asynchronous byte fifo. Removable for three source code, I do not know the three procedures can be arrived)