ORG 0000HLJMP MAINORG 0030HMAIN: MOV A,#0FEHLOOP: MOV P0,A RL A MOV R7,#100 ;可以由用户改变这个延时值 LCALL DELAY SJMP LOOPDELAY: MOV R2,#20DLY: MOV R3,#250 DJNZ R3,$ DJNZ R2,DLY DJNZ R7,DELAY RET END