单片机除法.txt

这是一个在51单片机上用汇编实现的除法程序。

TCOUNT         EQU    43H;  43H 44H 45H    ;除法结果
W              EQU    5FH;  5FH 60H 61H    ；被除数
STEP           EQU    4EH                  ；除数


             ORG    0000H  
RESET:       AJMP   MAIN                            
                 
             ORG       0300H                    

MAIN:                          



MOV   R0,#TCOUNT;
      MOV   R1,#03H;
INIA: MOV   @R0,#00H;   /* INITIALIZE TOTALCOUNT = Y*1000/STEP */
      INC   R0;
      DJNZ  R1,INIA; 
      
                                          
SBA:  MOV   R0,#W;     /* TCOUNT=W/STEP */
      MOV   R7,#02H;
      CLR   C;
      MOV   A,@R0;
      SUBB  A,STEP;
      MOV   @R0,A;
LSUBA:INC   R0;
      MOV   A,@R0
      SUBB  A,#00H
      MOV   @R0,A
      DJNZ  R7,LSUBA
      
CMPA: CJNE  A,#00H,TOTAL; 
      DEC   R0;
      MOV   A,@R0;
      CJNE  A,#00H,TOTAL;
      DEC   R0;
      MOV   A,@R0;
      CJNE  A,STEP,XX;
      AJMP  TOTAL;
XX:   JC    ABX;
TOTAL:MOV   R0,#TCOUNT;    /* TOTAL IS USED TO MAKE TOTALCOUNT++ */
      MOV   R1,#02H;
      CLR   C;
      MOV   A,@R0;
      ADD   A,#01H;
      MOV   @R0,A;
LT1:  INC   R0;
      MOV   A,@R0;
      ADDC  A,#00H;
      MOV   @R0,A;
      DJNZ  R1,LT1;
      AJMP  SBA
ABX:  MOV   R0,#TCOUNT; /* ABX USED TO REMEND TCOUNT */
      MOV   R1,#02H;
      CLR   C;
      MOV   A,@R0;
      ADD   A,#01H;
      MOV   @R0,A;
LT2:  INC   R0;
      MOV   A,@R0;
      ADDC  A,#00H;
      MOV   @R0,A;
      DJNZ  R1,LT2;