资 源 简 介
一、 使用键盘显示接口芯片8279接收按键键值，并在七段数码管上显示出来，通过判断键值进入相应音乐播放处理程序。在音乐播放程序中，使用定时器/计数器8253的计数器2，使其工作在方式¬ ¬ 3―方波发生器，通过查表依次取出乐曲频率值送入计数器作为计数初值，经out2输出方波，驱动扬声器发出不同频率的声音，在每个音阶之间加入相应的延迟时间，即实现了音乐的播放。-First, the use of a keyboard display interface chip receive keys keys 8279, and Seven-Segment LED display, through to determine the corresponding music player keys to enter the treatment program. Procedures in the music player, use the timer/counter 2 counter 8253 to work in the way ? ? 3- square-wave generator, followed by out music through the look-up table values into the counter as a frequency count of the initial value, the output side out2 waves, driven loudspeakers of different frequency sound, in between each scale by adding the appropriate delay time, namely, the realization of the music player.
