按下SW1按钮时，八个发光二极管（L1—L8）呈顺时针方向暗点流动；按下SW2按钮时，呈顺时针方向亮点流动；分别按下SW3、SW4按钮时，与上述流动方向相反，但效果相同；无键按下时，程序恢复初始状态，即停止运行。-When you press the button SW1, eight light-emitting diodes (L1-L8) showed a dark spot clockwise flow　when you press the SW2 button on a clockwise direction highlights flow　respectively press SW3, SW4 when the button above the flow in the opposite direction but the same effect　no key is pressed, the program resumes the initial state, it stops running.