微机原理课件ch042章节.pptVIP

Miscellaneous MOVSX is move and sign extend; MOVZX is move and zero-extend For different size register operation * 第*页 Miscellaneous BSWAP Convert between little endian form with big endian form CMOV Conditional move Depends on the last flags influenced by some prior instructions * 第*页 Segment Override Prefix Segment override prefix can be added to almost any instructions in the memory addressing mode JMP and CALL instruction can be used with segment override prefix Example MOV AX, ES:[DI] LODS ES:DATA1 * 第*页 Assembler(汇编程序) Directive(伪指令) Storing Data in a memory segment (定义指令) DB, define byte DW, define word, 2 byte DD, define doubleword, 4 bytes DQ, define quadword, 8 bytes DT, define ten bytes DUP (占位指令) ?, location reservation, initialized with 0 ALIGN (对齐指令) ALIGN 2 ALIGN 4 ALIGN 8 * 第*页 Assembler(汇编程序) Directive(伪指令) EQU, THIS, ORG, ASSUME TEN EQU 10 DATA1 EQU THIS BYTE ORG 100H (改变偏移地址) ASSUME CS:CODE_SEG PROC, ENDP Memory Organization MODELs Tiny, small, medium, large, huge * 第*页 Assembly Program .MODEL TINY/SMALL .386 .DATA DATA1 DB/DW/DD 50 dup(?) ;comment .CODE .STARTUP MOV CX, 50 AGAIN: MOV AX, ES:[046CH] INC BX LOOP AGAIN .EXIT END * 第*页 Homework 第一部分 6,7,8,10,19,21,24,28,36 * 第*页 The Intel Microprocessors Chapter 4Data Movement Instructions Instructor：Dr. Shen Runjie Content Assembler Machine Language PUSH/POP LOAD Effective Address String Data Transfer Miscellaneous Data Transfer Instructions Segment Override Prefix * 第*页 Why for Machine Ianguage Instructions Luckily we do not often need to code into hexadecimal form Using an assembler. Assembler translates assembly code into machine language Machine language is the native binary code μP understands The reason for introducing the Machine language Instruction Settle up a feeling for the way instructions are coded Understand why different instruction contain different numbers of bytes Help generating efficient code * 第*页 Instruction Modes Instructions o