微机原理课件ch02英文.pptVIP

Protected Mode Memory Addressing * 第*页 Protected Mode Memory Addressing 选择子-段寄存器内容 * 第*页 Protected Mode Memory Addressing * 第*页 Protected Mode Memory Addressing AV:段有效无效 D:访问寄存器和存储器数据模式16位，32位 * 第*页 Protected Mode Memory Addressing 程序不可见寄存器（cache） * 第*页 GDTR(全局描述符表寄存器) IDTR(中断描述符表寄存器) LDTR(局部描述符表寄存器) TR（任务寄存器） * 第*页 内存分页（memory paging mechanism） 自学 * 第*页 Homework 第一部分 8,10,13,14,20 第二部分（中文，500字） 通过互联网，查询并简要写出分页机制的工作原理 * 第*页 This part has been deprecated in the new version textbook. General Purpose Registers General Purpose Register EBX: Base Index: Used by several addressing mode instructions to hold the base of a block of data to be manipulated. A block usually contains some related data, e.g. a message to print in ASCII ECX: Count: Used by instructions such as REP and LOOP as a counter, e.g if CX = 10 then the LOOP instruction will loop 10 times decreasing CX until it reaches zero Also used by the Shift (SHR, SHL) and Rotate (ROR, ROL) instructions to indicate how many bits to shift or rotate * 第*页 General Purpose Registers General Purpose Register EDX: Data: Used by I/O (IN, OUT) instructions to hold the address of the port being accessed Used by the Multiply (MUL) and Divide (DIV) instructions to hold the result of 32-bit data manipulations Also used by BIOS to set up cursor positions * 第*页 General Purpose Registers ESP: Stack Pointer: Used by the stack, call and return instructions. EBP: Base Pointer: Holds the base pointer for memory data transfers. EDI: Destination Index: Holds the base destination pointer for string instructions. ESI: Source Index: Holds the base source pointer for string instructions. * 第*页 General Purpose Registers EIP: Instruction Pointer: register that points to the next instruction to be executed in the RAM If a 2 byte instruction is currently being executed at 0100, then IP = 0102 IP has a range from 0000 (0000 decimal) to FFFF (65535 decimal) This means that the CPU can only access up to 64K bytes of instructions using the IP re