start: mov ax ,2 mov cx,11 s: add ax , ax loop s
时间: 2024-05-31 18:10:41 浏览: 14
这是一段 x86 汇编语言的代码,它的作用是将寄存器 AX 的值乘以 2,然后将 CX 的值减 1,直到 CX 的值为 0。代码执行完毕后,AX 中的值将是 2 的 11 次方,即 2048。
具体来说,这段代码的含义为:
1. 将 2 存储到 AX 寄存器中。
2. 将 11 存储到 CX 寄存器中。
3. 执行循环,每次循环将 AX 的值加倍,CX 的值减 1。
4. 当 CX 的值为 0 时,跳出循环。
注意,这段代码没有任何输出语句,所以在执行过程中不会有任何输出。如果你希望在执行过程中查看 AX 和 CX 的值,可以在代码中添加相应的语句来输出它们的值。
相关问题
以子程序的形式改写assume cs:code data segment db 'welcome to masm!' db 2,36,113 data ends code segment start: mov ax,data mov ds,ax mov bx,0 mov di,16 mov ax,0b800h mov es,ax mov si,16012+352 mov cx,3 s: mov ah,ds:[di] push cx mov cx,16 s1: mov al,ds:[bx] mov es:[si],ax add si,2 inc bx loop s1 pop cx add si,128 inc di mov bx,0 loop s mov ax,4c00h int 21h code ends end start
Sure, here is the code rewritten as a subroutine:
```
data segment
db 'welcome to masm!'
db 2,36,113
data ends
code segment
start:
mov ax, data
mov ds, ax
call print_message ; call the print_message subroutine
mov ax, 4c00h
int 21h
print_message:
push ax
push bx
push cx
push di
push si
push es
mov bx, 0
mov di, 16
mov ax, 0b800h
mov es, ax
mov si, 16012+352
mov cx, 3
print_loop:
mov ah, ds:[di]
push cx
mov cx, 16
print_char_loop:
mov al, ds:[bx]
mov es:[si], ax
add si, 2
inc bx
loop print_char_loop
pop cx
add si, 128
inc di
mov bx, 0
loop print_loop
pop es
pop si
pop di
pop cx
pop bx
pop ax
ret
code ends
end start
```
The `print_message` subroutine takes care of printing the message to the screen, while the `start` routine sets up the data segment, calls the `print_message` subroutine, and then ends the program.
In addition, the `print_message` subroutine saves and restores the registers it uses to prevent them from being overwritten by other parts of the program.
将下面代码排列成正确格式 org 0x7c00start: mov ax, cs mov ds, ax mov es, ax ; 清屏 xor ax, ax mov es, ax mov di, 0 mov cx, 80 * 25 mov ax, 0x0720 rep stosw ; 输出字符串 mov si, str mov ah, 0x0eprint: lodsb cmp al, 0 je_sum int 0x10 jmp print ; 计算ASCII值的总和calc_sum: mov si, str xor cx, cxsum_loop: lodsb cmp al, 0 je end add cx, ax jmp sum_loop ; 显示ASCII值的总和end: mov ax, cx mov bx, 10 xor cx, cx div bx push ax cmp ax, 0 jz print_sum jmp endprint_sum: pop ax add al, '0' mov ah, 0x0e int 0x10 jmp endstr db "21210929周何昊然", 0times 510-($-$$) db 0dw 0xaa55```
```assembly
org 0x7c00
start:
mov ax, cs
mov ds, ax
mov es, ax
; 清屏
xor ax, ax
mov es, ax
mov di, 0
mov cx, 80 * 25
mov ax, 0x0720
rep stosw
; 输出字符串
mov si, str
mov ah, 0x0e
print:
lodsb
cmp al, 0
je end
int 0x10
jmp print
; 计算ASCII值的总和
calc_sum:
mov si, str
xor cx, cx
sum_loop:
lodsb
cmp al, 0
je end
add cx, ax
jmp sum_loop
; 显示ASCII值的总和
end:
mov ax, cx
mov bx, 10
xor cx, cx
div bx
push ax
cmp ax, 0
jz print_sum
jmp end
print_sum:
pop ax
add al, '0'
mov ah, 0x0e
int 0x10
jmp end
str db "21210929周何昊然", 0
times 510-($-$$) db 0
dw 0xaa55
```