说明：  目标器件: C8051F02x 编译工具: Silicon Laboratories IDE 程序说明: 此程序动态扫描键盘，当有按键按下时，将此键转换成对应的数字键值，同时蜂鸣器响一声
(target Components : C8051F02x compiler tools : Silicon Laboratories IDE procedures Note : This procedure dynamic scanning keyboard, When a button press, this bond converted into the corresponding figures for the pair, while buzzer ring for say)