请用8086汇编语言编写一个函数，功能是实现寻找一个输入的字符串中ASCII码最小的元素

以下是用8086汇编语言编写的函数，实现了寻找一个输入的字符串中ASCII码最小的元素：

; Function: find_min_ascii
; Description: find the minimum ASCII character in a string
; Input:
;   SI: pointer to the input string
; Output:
;   AL: the minimum ASCII character found in the string

find_min_ascii:
    mov al, [si]        ; initialize AL with the first character
    inc si              ; move to the next character
    cmp al, 0           ; check if the string is empty
    je done             ; if so, return the initial value in AL
    
loop:
    mov bl, [si]        ; load the next character into BL
    cmp bl, 0           ; check if it is the end of the string
    je done             ; if so, return the minimum ASCII found in AL
    cmp bl, al          ; compare the current character with the minimum found so far
    jb update           ; if the current character is smaller, update the minimum found so far
    inc si              ; move to the next character
    jmp loop
    
update:
    mov al, bl          ; update the minimum found so far
    inc si              ; move to the next character
    jmp loop
    
done:
    ret

该函数将输入字符串的指针存储在寄存器SI中，然后依次遍历字符串中的每个字符，并将其与当前找到的ASCII码最小的字符进行比较。如果找到更小的字符，则更新AL的值。最后，函数返回AL中存储的ASCII码最小的字符。