singlechip also call single-chip microcomputer,it is a sort of micro-controler integrated by CPU,RAM,ROM,timing,counting and varieties of 51 singlechip is the most typical and representive one thereinto,it has extensive application in all topic has designed a sort of music doorbell which is controled by the singlechip music doorbell system is consisted of the singlechip small system ,extand LED display and the sound with singlechip assemble language,reach the result of alarming when pressing the button,and displaying note synchronism回头再译