PIC单片机的BCD码处理程序

1、    PIC单片机的BCD码处理程序PIC单片机的BCD码处理程序#definePAGEEJECTTITLE"BCDArithmeticRoutines:Ver1.0"*;BCDArithmeticRoutines;*LISTcolumns=120,WRAP,L=0include"17c42.h"CBLOCK0x20Lbyte,HbyteR2,R1,R0;mustmaintainR2,R1,R0sequencecountNum1,Num2ENDC;BCDequNum1HtempequNum1LtempequNum

2、2;PAGEORG0x0000;*PIC单片机的BCD码处理程序#define PAGE    EJECT    TITLE   "BCD Arithmetic Routines : Ver 1.0"*;                      BCD Arithmetic Routin

3、es;* LIST     columns=120, WRAP, L=0 include "17c42.h" CBLOCK   0x20  Lbyte, Hbyte R2, R1, R0             ;must maintain R2, R1, R0 sequence  count  Num1, Num2 

4、ENDC;BCD     equ      Num1Htemp   equ      Num1Ltemp   equ      Num2; PAGE ORG     0x0000;*;          

5、60;           BCD Arithmetic Test Program;*;main setf     Hbyte setf     Lbyte;                    &

6、#160;          ;16bit binary num = 0xffff call    B2_BCD_Looped   ; after conversion the Decimal Num;                    

7、0;          ; in R0, R1, R2 = 06,55,35 setf     Hbyte setf     Lbyte call    B2_BCD_Straight ; sameasabove, but straight line code; movlw    0x06 movwf 

8、60;   R0 movlw    0x55 movwf     R1 movlw    0x35 movwf     R2              ; setf R0R1R2 = 65535; call    BCDtoB&#

9、160;         ; after conversion Hbyte = 0xff;                               ; and Lbyte = 0xff movlw 

10、;   0x99 movwf     Num1 movlw    0x99 movwf     Num2            ; setf Num1 = Num2 = 0x99 (maxBCD); call    BCDAdd     &

11、#160;    ; after addition, Num2 = 98;                               ; and Num1 = 01 ( 99+99 = 198); movlw    0x63&#

12、160;           ; setf Wreg= 63 hex call    BinBCD          ; after conversion, BCD = 99;                &

13、#160;              ; 63 hex = 99 decimal.;self    goto    self; PAGE;*;                  Binary To BCD Conversion R

14、outine (8 bit);       This routine converts the 8 bit binary number in the W Reg; to a 2 digit BCD number in location BCD( compacted BCD Code);       The least significant digit is returned in location LSD and; the most significant digit is

15、 returned in location MSD.;   Performance :;               Program Memory  : 10;               Clock Cycles    :  62

16、0; (worst case when W = 63 Hex );                                      ( i.e max Decimal number 99 );*;BinBCD 

17、clrf     BCDagain addlw    -10 btfss      _carry goto    swapBCD incf     BCD goto    againswapBCD addlw    10 swapf    BCD&#

18、160;iorwf     BCD return; PAGE;*;                Binary To BCD Conversion Routine (16 Bit);                 &#

19、160;     (LOOPED Version);      This routine converts a 16 Bit binary Number to a 5 Digit; BCD Number.;       The 16 bit binary number is input in locations Hbyte and; Lbyte with the high byte in Hbyte.;   

20、0;   The 5 digit BCD number is returned in R0, R1 and R2 with R0; containing the MSD in its right most nibble.;   Performance :;               Program Memory  :  32;      

21、;         Clock Cycles    :  750;*;B2_BCD_Looped bsf      _fs0 bsf      _fs1            ; set fsr0 for no auto increment;

22、0;bcf      _carry clrf     count bsf      count,4         ; set count = 16 clrf     R0 clrf     R1 clrf   

23、0; R2loop16a rlcf     Lbyte rlcf     Hbyte rlcf     R2 rlcf     R1 rlcf     R0; dcfsnz   count returnadjDEC movlw    R2  

24、0;           ; load R2 as indirect address ptr movwf     fsr0 call    adjBCD; incf     fsr0 call    adjBCD; incf     fsr0 call

25、0;   adjBCD; goto    loop16a;adjBCD movfp    indf0,wreg addlw    0x03 btfsc      wreg,3          ; test if result > 7 movwf    

26、 indf0 movfp    indf0,wreg addlw    0x30 btfsc      wreg,7          ; test if result > 7 movwf     indf0         

27、;  ; save as MSD return;*;                Binary To BCD Conversion Routine (16 Bit);                      

28、; (Partial Straight Line Version);      This routine converts a 16 Bit binary Number to a 5 Digit; BCD Number.;       The 16 bit binary number is input in locations Hbyte and; Lbyte with the high byte in Hbyte.;     

29、0; The 5 digit BCD number is returned in R0, R1 and R2 with R0; containing the MSD in its right most nibble.;   Performance :;               Program Memory  :  44;        

30、;       Clock Cycles    :  572;*;B2_BCD_Straight bsf      _fs0 bsf      _fs1            ; set fsr0 for no auto increment; bcf 

31、;     _carry clrf     count bsf      count,4         ; set count = 16 clrf     R0 clrf     R1 clrf     R2loop1

32、6b rlcf     Lbyte rlcf     Hbyte rlcf     R2 rlcf     R1 rlcf     R0; dcfsnz   count return          

33、0;        ; DONE movlw    R2              ; load R2 as indirect address ptr movwf    fsr0; adjustBCD movfp    indf0,wreg addlw 

34、60;  0x03 btfsc    wreg,3          ; test if result > 7 movwf    indf0 movfp    indf0,wreg addlw    0x30 btfsc    wreg,7    

35、60;     ; test if result > 7 movwf    indf0           ; save as MSD; incf     fsr0; adjustBCD movfp    indf0,wreg addlw    0x03 btfsc

36、0;   wreg,3          ; test if result > 7 movwf    indf0 movfp    indf0,wreg addlw    0x30 btfsc    wreg,7          ;

37、 test if result > 7 movwf    indf0           ; save as MSD; incf     fsr0; adjustBCD movfp    indf0,wreg addlw    0x03 btfsc    wreg,3 &#

38、160;        ; test if result > 7 movwf    indf0 movfp    indf0,wreg addlw    0x30 btfsc    wreg,7          ; test if result > 7 m

39、ovwf    indf0           ; save as MSD; goto    loop16b; PAGE;*;               BCD To Binary Conversion;      

40、This routine converts a 5 digit BCD number to a 16 bit binary; number.;       The input 5 digit BCD numbers are asumed to be in locations; R0, R1 & R2 with R0 containing the MSD in its right most nibble.;       The 16 bit binary num

41、ber is output in registers Hbyte & Lbyte; ( high byte & low byte repectively ).;       The method used for conversion is :;               input number X = abcde ( the 5 digit BCD number );

42、0;      X = (R0,R1,R2) = abcde = 10101010a+b+c+d+e;   Performance :;               Program Memory  :  30;             &#

43、160; Clock Cycles    :  112;*;mpy10b andlw    0x0f addwf     Lbyte btfsc      _carry incf     Hbytempy10a bcf      _carry     

44、;     ; multiply by 2 rlcf     Lbyte,w movwf     Ltemp rlcf     Hbyte,w         ; (Htemp,Ltemp) = 2*N movwf     Htemp; bcf  &

45、#160;   _carry          ; multiply by 2 rlcf     Lbyte rlcf     Hbyte bcf      _carry          ; multiply by 2 rlcf

46、     Lbyte rlcf     Hbyte bcf      _carry          ; multiply by 2 rlcf     Lbyte rlcf     Hbyte     ; (Hbyte,

47、Lbyte) = 8*N; movfp    Ltemp,wreg addwf     Lbyte movfp    Htemp,wreg addwfc    Hbyte return                   

48、0; ; (Hbyte,Lbyte) = 10*N;BCDtoB clrf     Hbyte movfp    R0,wreg andlw    0x0f movwf     Lbyte call    mpy10a          ; result = 10a+b; swa

49、pf    R1,w call    mpy10b          ; result = 1010a+b; movfp    R1,wreg call    mpy10b          ; result = 101010a+b+c; swapf    R2,w call    mpy10b