四个拨码开关，拨上去对应的前四个LED灯亮，体现了pld io功能的灵活。请把拨码开关右上方的跳线帽跳上，同时拔掉ADC0804的跳线帽。-Four DIP switches, dial up the corresponding first four LED lights, reflect the function of flexible pld io. Please dial code switch at the top right of the jumper cap jumped, and