Chapter2.2 Instruction MOV.pptVIP

* * * * * * 微机原理与接口技术Theory and Interface Technology of Microcomputer 北京化工大学 信息科学与技术学院 主讲教师： 郭青 guoqing@mail.buct.edu.cn Chapter 2 INSTRUCTION SET * 2.2 Data Movement Instructions * Objective Explain the operation of each data movement instruction with applicable addressing modes. Select the appropriate assembly language instruction to accomplish a specific data movement task 2.2.1 General Purpose Transfer * MOV dest, src Source 源操作数 Destination 目标操作数 never change usually change The MOV instruction transfers bytes or words of data between registers, or between registers and memory in the 8086 双操作数指令 1. MOV Instruction MOV * The operands can be byte or word The destination and source can use varying addressing modes Transfer data between Two registers Register and memory Segment register and register/memory Transfer immediate data to register/memory Memory to memory Immediate data to segment register Two segment registers Invalid transfer MOV * MOV SI, BX MOV DS, AX MOV AX, DS MOV AL, 5 MOV BYTE PTR [2000H], 5 MOV WORD PTR [BX], 5 MOV [2000H], AX MOV [2000H], DS MOV DISP[BX], CX MOV AX, DISP[SI] MOV AX, DISP[BX][SI] ；寄存器至寄存器 ；寄存器至段寄存器 ；段寄存器至寄存器 ；立即数至寄存器 ；立即数至存储单元，直接寻址 ；立即数至存储单元，寄存器间接寻址 ；寄存器至存储单元，直接寻址 ；段寄存器至存储单元，直接寻址 ；寄存器至存储单元，基址寻址 ；存储单元至寄存器，变址寻址 ；存储单元至寄存器，基址加变址寻址 MOV * Example： Use a MOV instruction to accomplish following task ： 1)??Set AL?as 69H 2)??Clear the word type memory location 2100H 3)??Transfer a byte from memory (addressed by BX) to CL 1) MOV AL，69H 2) MOV WORD DTR [2100H]，00H 3) MOV CL，[BX] 2. PUSH / POP * Store and retrieve data from the LIFO (last-in, first-out) stack memory. PUSH src ; (SP) ← (SP) – 2 ((SP) + 1 ：(SP)) ← (src) POP dest ; (dest) ← ((SP) + 1 ：(SP)) (SP) ← (SP) + 2 Operands (word type): Register Segment register ( POP CS is invalid) memory PUSH/POP * Stack holds data temporarily and stores return addresses for procedures. Stack memory is a LIFO (last-in, first-out) memory. 存取规则：先入后出，后入先出