并行数据流转换为一种特殊的串行数据流 重点在通信协议的实现上 注意同一时钟驱动几个信号时，若信号需要分别使用跳变沿或电平有效，那么分别用时钟的不同沿进行驱动-Parallel data streams into a special kind of serial communication protocol data stream focuses on the realization of the same clock-driven attention to a few signals,