用数码管前两位显示一个十进制数，变化范围为00~59，开始时显示00，每按下S2键一次，数值加1；每按下S3键一次，数值减1；每按下S4键一次，数值归零；按下S5键一次，利用定时器功能使数值开始自动每秒加1，再次按下S5键，数值停止加1，保持显示原数。-Digital tube first two shows a decimal number, range 00 to 59, the beginning of display 00, press S2 button once, incremented by 1　press S3 button once, the value minus 1　Each time you press S4 button. time, the value zero　press the S5 key once, use the timer feature allows the value to start automatically every second plus 1 is pressed again the S5 key values ​ ​ stop plus 1, to maintain the original number is displayed.