说明：  微机实验8255 1)用8个LED来反映8个开关量的状态，拨动开关，让对应的灯亮。 2)8255控制交通灯 本设计用LED来模拟交通灯。请考虑8255与LED的连接，以及如何用8255来控制LED的点亮与熄灭。 交通灯的控制过程： 东西向的绿灯、南北向的红灯亮5秒钟。 东西向的绿灯灭、南北向的红灯亮，在此时间段中东西向的黄灯闪烁5次，每次亮0.5秒灭0.5秒。 南北向的绿灯、东西向的红灯亮5秒钟。 南北向的绿灯灭、东西向的红灯亮，在此时间段中南北向的黄灯闪烁5次，每次亮0.5秒灭0.5秒。 按此规则重复控制。
(Microcomputer Lab 82551) with eight LEDs to reflect the status of the eight switch, toggle switch, so that the corresponding lights. 2) 8255 the design of the control of traffic lights with LED to simulate traffic lights. Please consider the 8255 LED connection, as well as how to use 8255 to control the LED lit and extinguished. Traffic light control process: things green light to the north and south to the red light for 5 seconds. Green light off of the east-west and north-south red light, something to the yellow light flashes 5 times in this time period, every time bright 0.5 seconds every 0.5 seconds. The green light of the north-south, east to west, the red light is on for 5 seconds. Green light off of the north-south, east-west red light, in this period of time in the north and south to the yellow light flashes 5 times, and every time bright 0.5 seconds every 0.5 seconds. This rule repetitive control.)