说明：  针对I/O的数字设计解决方案 数字电路设计者采用了一系列方法来提高信号速度和消除I/O问题。例如，采用差分信号处理来 提高芯片间的通信速度。信号同步、源同步和自同步之类的设计方法改善了内部IC（集成电路） 通信，在满足计算机行业所需速度的前提下，提供了可靠的输入/输出。
(In the micro-computer systems, CPU basic communication with the outside there are two types of parallel data communication that you transmit at the same time, the advantage of faster transfer speeds, but the data how many how many transmission lines needed and the data in a serial communication send an order, to save transmission lines. With Vefilog HDL language to implement string and and the conversion between the serial communication interface)