程序实现的功能是控制P3口的8个发光二极管从右向左逐一点亮并熄灭。其中P3口输出逻辑电平“0”时控制发光二极管点亮，输出逻辑电平“1”时控制发光二极管熄灭。-Program function is to control the port P3 eight light-emitting diodes from right to left one by one lit and extinguished. Control port P3 output logic level " 0"