ORG 000H
AJMP START
ORG 000BH
AJMP TIME0
ORG 30H
START:MOV P1£¬#0FFH
MOV R7£¬zz#00H
MOV TMOD,#00000001B
MOV TH0£¬#3CH
MOV TL0£¬#0B0H
SETB EA
SETB ET0
SETB TR0
LOOP:AJMP LOOP
TIME0£º
INC R7
MOV A,R7
CJNE A,#20£¬T_RET
T_L1£ºCPL P1.0
MOV R7£¬#0
T_RET:MOV TH0£¬#3CH
MOV TL0£¬#0B0H
RETI
END
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ŽÍÄã¸ÄÁËһϣ¬Õý´_ŸoÕ`£º
ORG 000H
AJMP START
ORG 000BH
AJMP TIME0
ORG 30H
START:
MOV P1,#0FFH
MOV R7,#150
MOV R6,#2
MOV TMOD,#00000001B
MOV TH0,#3CH
MOV TL0,#0B0H
SETB EA
SETB ET0
SETB TR0
LOOP:
AJMP LOOP
TIME0:
DJNZ R7,T_RET
MOV R7,#150
DJNZ R6, T_RET
MOV R6,#2
CPL P1.0
T_RET:
MOV TH0,#3CH
MOV TL0,#0B0H
RETI
END
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