外部中断.asm

AD AND TLC549 TLC548C, TLC548I, TLC549C, TLC549I

SEC   DATA 30H
RUN   BIT  P3.0
      ORG 0000H
      AJMP MAIN

      ORG 0003H
      MOV SEC,#0
      RETI

      ORG 000BH
      AJMP IINT0

      ORG 0030H
MAIN: MOV SP,#60H
      MOV R6,#10
      SETB RUN
      MOV TMOD,#01H
      MOV TL0,#LOW(-50000)
      MOV TH0,#HIGH(-50000)
      MOV IE,#10000011B
      SETB IT0  ;CLR IT0
      SETB TR0

loop0:MOV A,SEC
      CPL A
      MOV P1,A
      SJMP LOOP0   

IINT0:PUSH ACC
      PUSH PSW
      MOV TL0,#LOW(-50000)
      MOV TH0,#HIGH(-50000)
      DJNZ R6,LOOP3
      MOV R6,#10
      JNB RUN,LOOP3  ;RUN/STOP
      INC SEC
LOOP3:POP PSW
      POP ACC
      RETI
   
      END