bcd.asm

通过调试的有用的单片机控制程序

;*********固定单元的BCD码转换****************
;*********小数与不带小数的两种***************
;*********插表方式混合显示*******************
;********************************************
ORG     0000H
HDAT    EQU     43H     ;十六数据的收地址
BDAT    EQU     47H     ;
EDAT    DATA    48H     ;
DISD    EQU     57H     ;
BXCOUNT   EQU     08H
AJMP    BCDE
;BCD码转换程序段
BCDE:   CLR     A
        CLR     F0      ;存储C位，使到移位的数据能恢复
        MOV     R2,#32        
HBCH:   CLR     C
        MOV     R6,#4
        MOV     R0,#HDAT
        MOV     R1,#BDAT
        MOV     C,F0
HCH:    MOV     A,@R0
        RLC     A
        MOV     @R0,A
        DEC     R0
        DJNZ    R6,HCH
        MOV     F0,C
        MOV     R6,#4        
BCH:    MOV     A,@R1
        ADDC    A,@R1
        DA      A
        MOV     @R1,A
        DEC     R1
        DJNZ    R6,BCH
        DJNZ    R2,HBCH
        MOV     R6,#4
        MOV     R0,#HDAT
        MOV     C,F0
HCHE:   MOV     A,@R0   ;因为带C位循环的移位是33次才能把原来数据恢复
        RLC     A
        MOV     @R0,A
        DEC     R0
        DJNZ    R6,HCHE
;查表，找出相应的笔型码，并送到对应的显示单元
PAND:   MOV     R0,#BDAT
        MOV     R1,#DISD
        MOV     A,#0
        MOV     B,EDAT
        MOV     R6,#0
        MOV     DPTR,#BXTAB0
PANL:   MOV     A,@R0
        ANL     A,#0FH
        XCH     A,R6
        CJNE    A,EDAT,NEXTPAN
        MOV     DPTR,#BXTAB1
NEXTPAN:XCH     A,R6
        MOVC    A,@A+DPTR
        MOV     @R1,A
        INC     R6
        DEC     R1
        MOV     DPTR,#BXTAB0
        MOV     A,@R0
        SWAP    A
        ANL     A,#0FH
        XCH     A,R6
        CJNE    A,EDAT,NEXTPAN0
        MOV     DPTR,#BXTAB1
NEXTPAN0:XCH    A,R6
        MOVC    A,@A+DPTR
        MOV     @R1,A
        INC     R6
        DEC     R1
        MOV     DPTR,#BXTAB0
        DEC     R0
        CJNE    R6,#BXCOUNT,PANL    
OUTHBCH:
        SJMP    $
BXTAB0: DB      0,1,2,3,4,5,6,7,8,9
BXTAB1: DB      10H,11H,12H,13H,14H,15H,16H,17H,18H,19H
        END