5.6 十进制和十六进制转换，lea指令，写注释

1. 将十进制100转换成十六进制64

assume cs:codesg,ds:data,ss:stack
data segmeNT
	str db '00000100','$'
data ends

stack segment
	db 10 dup(0)
stack ends

codesg SEgment
    start:
    
    mov ax,data
	mov ds,ax
	
	mov bx,0
	mov cx,8
	mov ax,0
	s:
		mov dx,ax
		shl ax,1
		shl ax,1
		shl ax,1
		shl dx,1
		add ax,dx
;乘10
		add al,str[bx]
		adc ah,0
		sub ax,30h
		
		inc bx
		loop s
	
	
	mov ah,4ch
    int 21h

codesg ends
end start

comment*
string str = "00000100"
int res = 0
for (int i = 0; i < 8; i++)
    res = res * 10 + str[i] - '0';
return res
*comment

2. 将10进制12345转换为16进制3039并且输出

2.1 将10进制12345转换为16进制并存到内存当中

assume cs:codesg,ds:data,ss:stack
data segmeNT
	str db '00012345','$'
	res db '0000','$'
data ends

stack segment
	db 100 dup(0)
stack ends

codesg SEgment
    start:
    
    mov ax,data
	mov ds,ax
	mov ax,stack
	mov ss,ax
	mov sp,10
	mov si,4
	
	mov bx,0
	mov cx,8
	mov ax,0
	s:
		mov dx,ax
		shl ax,1
		shl ax,1
		shl ax,1
		shl dx,1
		add ax,dx
;乘10
		add al,str[bx]
		adc ah,0
		sub ax,30h
		
		inc bx
		loop s
;ax = 3039
	mov cx,4
	l:
		mov dx,ax
		and dx,0fh
		add dx,30h
		cmp dx,40h
		jb s1
		add dx,7h
;求出3039的ASCII码，push
	s1:
		dec si
		mov ds:res[si],dl
		shr ax,1
		shr ax,1
		shr ax,1
		shr ax,1
		loop l
	
	mov ah,4ch
    int 21h

codesg ends
end start

comment*
if (res = 0) ans++;

cmp ax,bx
jne s1
inc dx
s1:

if (x == 1) res = 10
else res = 20

mov res,10
cmp x,1
je s1
add res,10
s1:

*comment

2.2 将10进制12345转换为16进制并直接输出

• 在loop后面添上如下代码

;mov dx,offset res
lea dx,res
mov ah,9
int 21h