rev2.asm

51系列单片机的汇编程序包

  ORG 0000H
  AJMP REV
 REV:MOV TOMD,#20H
      MOV TH1,#F3H
      MOV TL1,#F3H
      SETB TR1
      MOV SCON,#50H
      MOV PCON,#80H
 RPT:MOV R5,#00H

      MOV R0,#30H
 TR0:JBC RI,TR1
      AJMP TR0
 TR1:MOV A,SBUF
 MOV R3,A
 ADD A,R5
 MOV R5,A
 TR2:JBC RI,TR3
 AJMP TR2
 TR3:
 MOV A,SBUF
 MOV @R0,A

 ADD A,R5
 MOV R5,A
 INC R0
 DJNZ R3,TR2
 TR7:JBC RI,TR8
 AJMP TR7
 TR8:MOV A,SBUF
 XRL A,R5

 JZ ERROR
 RET
 ERROR:ACALL ERRSTR
 DB 0DH,0AH
 DB'WRONG'
 DB 1BH
 TEXT:MOV A,R5
 MOV SBUF,A
 RET
 ERRSTR:POP DPH
 POP DPL
 CLR A
 MOVC A,@A+DPTR
 LOOP:MOV SBUF,A
 JNB TI,$
 CRL A
 MOVC A.@A+DPTR
 CJNE A,#1BH,LOOP
 MOV A,#1
 JMP @A+DPTR
 END