实验名称：SPI驱动74HC595，数码管显示实验

功能描述：利用数码管显示数据0~9999。

实验目的：熟悉SPI通信协议。

　　 熟练掌握查表法。

　　 了解人眼对显示的分辨能力。

　　 学习利用SPI驱动SPI器件74HC595。

　　 学会使用定时器定时。

目标芯片：ATMEGA128

内部8M晶振

　　 如果数码管刷新频率不够高的话将会出现闪烁的现象。-Experiment name: SPI driver 74HC595, digital tube display experiment Function Descr iption: With digital display data from 0 to 9999. Experimental Objective: Familiar SPI communication protocol. Master look-up table. Understanding of the human eye' s ability to distinguish the display. Learn to use SPI driver SPI devices 74HC595. Learn how to use the timer timed. Target Chip: ATMEGA128 internal 8M crystal if digital is not high enough refresh rate will be flickering.