7219display.asm

汇编代码包含7219驱动数码显示程序 程序里面已经包含了相关的设置说明。

addr_7219     equ     28h
data_7219     equ     29h
;------------------------------------
     org     0000h
     ljmp    init
     org     0030h
;------------------------------------
;对7219控制寄存器的初始化
init:
     mov     addr_7219,#09h      ;Decode Mode
     mov     data_7219,#0fh      ;对八个数码管进行译码
     lcall   dis_7219

     mov     addr_7219,#0ah      ;Intensity
     mov     data_7219,#0ah
     lcall   dis_7219

     mov     addr_7219,#0bh      ;Scan Limit
     mov     data_7219,#07h      ;设定扫描八个显示器
     lcall   dis_7219

     mov     addr_7219,#0ch      ;Shutdown
     mov     data_7219,#01h
     lcall   dis_7219

     mov     addr_7219,#0fh      ;Display Test
     mov     data_7219,#00h      ;正常状态
     lcall   dis_7219
;------------------------------------
main_loop:
     lcall   delay
     lcall   change
     ljmp    main_loop
;------------------------------------
;in:
;out:
;fun:利用7219来显示
;var:addr_7219,data_7219,r4,r5,r6,r7
;------------------------------------
dis_7219:
     mov     a,addr_7219           ;送地址
     mov     r7,#08h
     clr     c
     clr     p1.0
dis_lp0:
     rlc     a
     mov     p3.0,c
     setb    p3.1
     nop
     nop
     clr     p3.1
     djnz    r7,dis_lp0
     mov     a,data_7219           ;送数据
     mov     r7,#08h
     clr     c
dis_lp1:
     rlc     a
     mov     p3.0,c
     setb    p3.1
     nop
     nop
     clr     p3.1
     djnz    r7,dis_lp1
     setb    p1.0
     ret
;------------------------------------
delay:
     mov     r7,#00h
     mov     r6,#00h
delay_1ms:
     djnz    r7,$
     djnz    r6,delay_1ms
     ret
;------------------------------------
change:
     mov     addr_7219,#xx         ;选择第几个数码管
     mov     data_7219,#xx         ;显示内容
     lcall   dis_7219
     ret