基于DE1的nios的串口sdram通信例程-Based on DE1' s nios serial communication routines sdram

对例程进行改编，实现按键，led,串口，显示屏，触摸屏相关功能 使用电阻触摸屏9341，任务间通过邮箱通信(For routine adaptation, key, led, serial port, display, touch screen related functions. Using resistive touch screen 9341, through mail communication between tasks)