hhh理现对交通信号灯进行管理，车辆放行3分钟后，车行道黄灯闪烁5秒钟，以警示车辆将切换红绿灯。此时人行横道仍维持红灯点亮。车行道的黄灯闪烁5秒钟后，转为人行横...

hhh理现对交通信号灯进行管理，车辆放行3分钟后，车行道黄灯闪烁5秒钟，以警示车辆将切换红绿灯。此时人行横道仍维持红灯点亮。车行道的黄灯闪烁5秒钟后，转为人行横道行人放行1分钟，然后再转为车行道车辆放行3分钟。如此循环重复。 用发光二极管模拟信号灯，8255A实现对信号灯的控制（所用端口自定），8253的计数器2定时向实验系统主片8259A的IRQ7请求中断，以实现3分钟，5秒钟和1分钟的定时。 实验系统8253计数器2的CLK2可接OPCLK，频率为1.19318MHZ，GATE2已接＋5V，定时可采用软硬件结合相结合的方式-HHH Jimmy is right for traffic signal management, vehicle clearance three minutes later, the driveway five seconds flashing yellow light to warn vehicles will switch traffic lights. This sees the red light remains lit. The flashing yellow light carriageway five seconds later, the pedestrian crossings to release a minute and then released into driveway vehicles for three minutes. So the cycle to repeat. Using light-emitting diode signal simulation, 8255A right signals control (used to set the port), the 8253 regular counter to the two experimental system of the main unit there 8259A interrupt request, to achieve 3 minutes, 5 seconds and one minute timing. Experimental System to the 8253 counter two OPCLK CLK2 access, frequen