SDH开销的接收处理，要求：

1，　　A1和A2字节为帧头指示字节，A1为“11110110”，A2为“00101000”，连续3个A1字节后跟连续3个A2字节表示SDH一帧的开始。要求自行设计状态机，从连续传输的SDH字节流中找出帧头。

2，　　E2字节为勤务话通道开销，用于公务联络语音通道，其比特串行速率为64KHz(8*8K=64)。要求从SDH字节流中，提取E2字节，并按照64K速率分别串行输出E2码流及时钟，其中64K时钟要求基本均匀。（输出端口包括串行数据和64K串行时钟）

-Receiving SDH overhead processing requirements: 1, A1 and A2 bytes instruction byte header, A1 is " 11110110" , A2 is " 00101000" , for three consecutive A1 bytes followed by three A2 bytes of an SDH the beginning of the frame. Asked to design a state machine, from the continuous stream of bytes in the SDH transmission header to find out. 2, E2-byte path overhead for the service, then, for the public to contact voice channels, the bit-serial rate 64KHz (8* 8K = 64). SDH byte stream request from the extraction E2 bytes, and the serial output in accordance with rates of E2 64K stream and clock, which clock requires 64K basic uniform. (Including the serial data output port and 64K serial clock)