汇编语言循环的问题
题目：按１５*１６列的表格形式显示ＡＳＣＩＩ码为１０Ｈ－１００Ｈ的所有字符，即以行为主的顺序及ＡＳＣＩＩ码递增的次序依次显示对应的字符．每１６个字符为一行，每行中相邻两个字符之间用空白符（ＡＳＣＩＩ码为０）隔开
datarea segment
datarea ends
prognam segment
main proc far
assume cs:prognam, ds:datarea, es:datarea
start: ;starting execution address
;set up stack for return
push ds
sub ax, ax
push ax
;set DS register to current data segment
mov ax, datarea
mov ds, ax
mov es, ax
;MAIN PART OF PROGRAM GOES HERE
mov dl, 10h
mov cx, 20h
mov ax, 101h
print:mov ah, 02h
int 21h
inc dl
push dx ；输出空格
mov dl, 0h
mov ah, 02h
int 21h
pop dx
dec cx
loop print
push dx ；输出换行回车
mov dx, 0Ah
mov ah, 02h
int 21h
mov dx, 0Dh
mov ah, 02h
int 21h
pop dx
cmp dx, ax ；前面都没问题，能显示一行和换行，只是加上这两行后
jnz print ；是死循环，这是怎么一回事呢
ret ;return to DOS
main endp ;end of main part of program
;---------------------------------------------------------------------
prognam ends ;end of code segment
;*********************************************************************
end start ;end assembly
