*循环与延时程序

*该程序的功能可使接在F206的XF,IO2引脚上的发光二极管（红、绿灯）交替闪烁，

*闪烁间隔为2s（亮2s，灭2s），闪烁总时间为2min

*程序中用到了用DSP实现的延时模块。该模块是采用指令延时来实现的，这在很多

*程序中都可以用到，但在严格的情况下应使用定时器产生延时以提高精度和CPU效率。-* Loop and delay procedures* function allows the connection of the program in the F206 XF, light-emitting diodes (red, green) IO2 pin flash alternately,* blink interval 2s (bright 2s, off 2s), flashes the total time To 2min* procedures used in the delay module with DSP implementation. This module is implemented using instruction latency, which can be used in many* program, but under strict conditions should be used to generate the delay timer to improve the accuracy and CPU efficiency.