首先分别向A口和B口写入80H和01H，然后分别将该数右移和左移一位，再送到端口上，这样循环下去，从而实现流水灯的显示。-A first written, respectively, to the port and the B port 80H and 01H, respectively, then the number of right and left one, and then sent on a port, so the cycle continues, in order to achieve water lights display.