display.asm

自制单片机实验板.rar

;*****************************************************
;
;     This programme is for study Ver2.0.0 beta
;This programme must be run in 12MHz standard settings
;              Display  programmer
;               Designer: Mr.Koii
;         Copyright 2002-2003 koiistudio
;     2003.03.31 at Changsha. H.N. P.R.China
;
;*****************************************************

;*****************************************************
;数码管显示
;*****************************************************

digital:	       mov     a,digital_bit                ;根据显示位置读取不同的显示内容
                       jb      acc.0,digital_check0
                       jb      acc.1,digital_check1
                       jb      acc.2,digital_check2
                       jb      acc.3,digital_check3
                       jb      acc.4,digital_check4
                       jb      acc.5,digital_check5
                       jb      acc.6,digital_check6
                       jb      acc.7,digital_check7
                       call    beep2
                       ret
digital_check0:        mov     r0,#digital_byte
                       mov     a,@r0                        ;秒
                       jmp     digital_display
digital_check1:        mov     r0,#digital_byte
                       inc     r0
                       mov     a,@r0
                       jmp     digital_display
digital_check2:        mov     r0,#digital_byte             ;分
                       inc     r0
                       inc     r0
                       mov     a,@r0
                       setb    acc.4                        ;加小数点
                       jmp     digital_display
digital_check3:        mov     a,#digital_byte
                       add     a,#3
                       mov     r0,a
                       mov     a,@r0
                       jmp     digital_display
digital_check4:        mov     a,#digital_byte              ;时
                       add     a,#4
                       mov     r0,a
                       mov     a,@r0
                       setb    acc.4                        ;加小数点
                       jmp     digital_display
digital_check5:        mov     a,#digital_byte
                       add     a,#5
                       mov     r0,a
                       mov     a,@r0
                       anl     a,#83h                       ;屏蔽无效位
                       jmp     digital_display
digital_check6:        mov     a,#digital_byte
                       add     a,#6
                       mov     r0,a
                       mov     a,#20h
                       jmp     digital_display
digital_check7:        mov     a,#digital_byte
                       add     a,#7
                       mov     r0,a
                       mov     a,#20h

digital_display:       push    a
                       mov     a,digital_flash_time
                       anl     a,#7fh                       ;最高位表示显示状态：1为显示;0为不显示;其余位为记数值
                       cjne    a,#80,digital_display_00
                       mov     a,digital_flash_time
                       cpl     acc.7
                       anl     a,#80h
                       mov     digital_flash_time,a
                       jmp     digital_display_01
digital_display_00:    inc     digital_flash_time
digital_display_01:    pop     a
                       jb      acc.7,digital_display_1      ;最高位表示现在是否选择了该位，若是则闪烁
digital_display_0:     mov     dptr,#data_tab_digital
                       movc    a,@a+dptr
                       cpl     a                            ;数据是共阴数码管的，用在共阳数码管上就需要取反
                       mov     p2,#0
                       mov     p0,a
                       mov     a,digital_bit
                       mov     p2,a
                       rl      a
                       mov     digital_bit,a
                       call    time2_5ms
                       ret

digital_display_1:      push    a
                        mov     a,digital_flash_time
                        jb      acc.7,digital_display_2
                        pop     a                           ;若最高位为零则消隐
                        mov     a,#20h
                        jmp     digital_display_0
digital_display_2:      pop     a                           ;否则正常显示
                        clr     acc.7
                        jmp     digital_display_0

;*****************************************************
;共阴数码管显示数据
;排列为：0-F, 0.-F.
;端口排列：p07   p06  p05  p04  p03  p02  p01  p00
;段排列为： d    dp    e    c    g    b    f    a
;*****************************************************

data_tab_digital:      db     0b7h,014h,0adh,09dh,01eh,09bh,0bbh,015h
                       db     0bfh,09fh,03fh,0bah,0a8h,0bch,0abh,02bh
                       db     0f7h,054h,0edh,0ddh,05eh,0dbh,0fbh,055h
                       db     0ffh,0dfh,07fh,0fah,0e8h,0fch,0ebh,06bh
                       db     000h