WebMay 2, 2012 · 2 Answers. Sorted by: 13. In the cases you're looking at, the byte ptr and word ptr don't accomplish much. While harmless, the assembler already "knows" that al and dl are byte-sized, and that bx is word-sized. You need something like byte ptr when (for example) you move an immediate value to an indirect address: mov bx, some offset mov [bx], 1. WebOct 20, 2024 · MOV CL, BYTE PTR AWORD ;get first byte MOV CL, BYTE PTR AWORD + 1 ;get second byte Field Values: type This field can have one of the following values: BYTE, WORD, DWORD, QWORD, TBYTE, NEAR, FAR. name This field can be: 1. A variable name. 2. A label name. 3. An address or register expression. 4. An integer that represents an offset.
设DS=8200H, SI=3942H, 指令“inc byte ptr [si]”操作数的物理地址 …
Webmov bl, al shr bl, 4 mov dl, tab[bx] mov byte ptr [si+2], dl mov bl, al 非负数:XXXXH,例如 10H 打印为 0010H 负数:-XXXXH,例如 0C898H 打印为-3768H。 要求: 设计一个子程序 PRINT、以上面指定的格式显示有符号数,参数传递采用自定的寄存器。 Web设DS=8225H,DI=3942H,指令INC BYTE PTR [DI] 操作数的物理地址是=(DS)×16+有效地址=82250+3942H=85B92H. INC BYTE PTR [DI]这个指令的含义:将该物理地址单元中的操作 … bishop tl craft
DEC BYTE PTR[BX+SI+006H]是什么寻址方式?-CSDN社区
WebMar 30, 2024 · 用byte ptr指明了指令访问的内存单元是一个字节单元。 mov byte ptr ds:[0], 1 inc byte ptr [bx] inc byte ptr ds:[0] add byte ptr [bx], 2 在没有寄存器参与的内存单元访问指 … WebApr 8, 2024 · Then add word ptr [freq_array + eax * 2], 1. In 32-bit code you can take advantage of its more powerful addressing modes (compared to 16-bit). Also note that your code would be unsafe if freq_array spans a 64k boundary; add si, ax could wrap without doing carry-out into the high bits of ESI. – Peter Cordes. Webint 21h ;do read bytes cmp byte ptr [si+18h],40h ;check relocation jb ChkFinF ;exit if not ok cmp word ptr [si+3ch],400h ;check NE offset ... inc word ptr [si+1ch] ;inc segment count mov ax,word ptr [si+1ch] ;ax=segment count dec ax ;ax=ax-1 mov cl,8 ;Assume Segs<255 mul cl ;multiply to get bytes bishop toal