说明：  8位单片机很多地方需要随机数，比如游戏的洗牌，可在timer中取数，但是随机数质 量不高。随机数是一个既简单又复杂的问题,这里的例子使用了众所周知的线性叠加法，没 有完美的方法产生随机数，不过线性叠加法是一个合适的方法,彻底解决8位机随机数的问 题。
(eight SCM need many random numbers, such as the shuffling game, in which a few timer. But random quality is not high. Random number is a simple and complicated issue, here's a well-known example of the use of the linear superposition method, no perfect method produces random numbers, but the linear superposition method is a suitable method, completely solve eight aircraft random problems.)