开机时，显示“0， 第一次按下时，显示“D1”；第二次按下时，显示“D1D2”；第三按下时，显示“D1D2D3”，8个全显示完毕，再按下按键下时，给出“嘀”提示音。-Turned on, displays " 0, for the first time pressed, the display"　D1 "　 second time pressed, the display"　D1D2 "　 the third press, the display"　D1D2D3 " , 8 full-show finished, and then press button next time, give " tick"　tone.