本实验由RESET健清0，PSW1健控制预制数，按下置入1234，PSW2控制正逆计数，按下递减计数，弹起正向计数-In this study, health clearance by the RESET 0, PSW1 prefabricated health control number, press into 1234, PSW2 control the forward and reverse count, press the count down, bounce forward coun