max543.asm

12位串行DA,精度可以满足较高的要求,自己做了一下,感觉效果还不错

;spi接口为p1.0,p1.1,p1.2

        clk equ p1.0
        sri equ p1.1
        load equ p1.2

        org 00h
        ajmp start
        org 20h
start:  mov r7,#0
begin:
        acall init
        acall init_
        acall init_da
        ajmp begin

init:
        mov dptr,#table 
        mov a,r7
        movc a,@A+dptr
        mov r1,a
        mov r2,#00
        mov r3,#8
        mov r4,#4
        ret

init_:  setb load
        clr sri
        clr clk
        ret


init_da:
        acall mobile
        acall delay
        acall _ad
        ret

mobile:
        clr c
loop:
        mov a,r1
        rlc a
        mov sri,c
        mov r1,a
        ;acall delay
        setb clk
        ;acall delay
        clr clk
        ;acall delay
        djnz r3,loop
        inc r7
        cjne r7,#61,LL
        mov r7,#0
ll:     clr c
loopl:
        mov a,r2
        rlc a
        mov sri,c
        mov r2,a
        ;acall delay
        setb clk
        ;acall delay
        clr clk
        ;acall delay
        djnz r4,loopl 
        ret

_ad:clr load
        ;acall delay
        ret

delay:mov r6,#10h
d1:djnz r6,d1
     ret
TABLE:	
DB 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
DB 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 
DB 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60
end