LJMP START
ORG 000BH
LJMP T0_INT
START:
MOV TMOD, #02H ;T0定時方式2
MOV TH0, #6 ;定時500us@6MHz
MOV TL0, #6
MOV IE, #82H
SETB TR0
MOV R7, #4
MOV R6, #125
SJMP $
T0_INT:
DJNZ R7, T0_EXIT
CPL P1.0 ;2000us翻轉壹次
MOV R7, #4
DJNZ R6, T0_EXIT
CLR TR0 ;500ms後,停止
CLR P1.0 ;靜態為低電平
T0_EXIT:
RETI
END