zxw2.asm

来自「这程序是实现单片机与PC机的通信程序 可供大家参考或学习！」· 汇编 代码 · 共 57 行

      ORG 0000H
      JMP BEGIN
BEGIN:MOV P2,#0FFH
      CALL INT_232
      L1: MOV R2,P2
      CJNE R2,#0EFH,E
      CALL TX
      MOV R3,#50
      CALL DELAY
      JMP L1
  E:  MOV R1,P2
      CJNE R2,#0DFH,L1
      CALL RX
      AJMP L1
INT_232:
      MOV SCON,#50H
      MOV TMOD,#20H
      MOV TH1,#0FDH
      SETB TR1
      SETB TI
      RET
 TX: 
      MOV DPTR,#TAB
      CLR A
      MOV R0,A
  R:  JNB TI,$
      CLR TI
      MOV A,R0
      MOVC A,@A+DPTR
      INC R0
      CJNE R0,#15,D
      CLR A
      MOV R0,A
      AJMP RE
  D:  
      MOV SBUF,A
      JMP R
      MOV R0,A
  RE: RET
 RX:  
      JNB RI,$
      CLR RI
      MOV A,SBUF
      JNB TI,$
      CLR TI
      MOV SBUF,A
      RET 
 DELAY:
     MOV R4,#50
  CC:MOV R5,#100
     DJNZ R5,$
     DJNZ R4,CC
     DJNZ R3,DELAY
     RET
 TAB:DB 'HAPPY NEW YEAR!'
      END