知识要点：理解熟悉散转结构的程序

运行结果：按P3.2 或3.3(低4 位的任意一个键盘)第一位数码管加1 直到9 循环

开始显示0把P3 送OFH,判断有没有按键,没有则反复循环,有按R0 加1,如到10

那么则清除, 最后根据R0 的值散转.-knowledge points : understanding the structure familiar to the casual result of running the program : by P3.2 or 3.3 (low four of arbitrary one keyboard), a digital tube until 9 plus one cycle beginning to show 0 P3 sent OFH judge has the keys were not repeated cycle, an increase by R0, so as to 10 were cleared, Finally, according to the value of R0 casual switch.