org 00h
ljmp start start: mov a,#0ffh ;设置移动初值 clr c ;清0 mov r4,#08h ;移动8次 loop: rlc a ;左移一位 mov p1,a ;输出至p1 lcall delay ;延迟200ms djnz r4,loop ;左移7次? mov r4,#07h ; loop1: rrc a mov p1,a lcall delay djnz r4,loop1 mov r4,#07h ret ;//==========延迟200ms============ delay: ;延迟200ms mov r1,#20 d1: ;延迟10ms mov r2,#20 d2: mov r3,#250 djnz r3,$ djnz r2,d2 djnz r1,d1 ret end |
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