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address spaces in protected-mode of Pentium

johnsecada
Beginner
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Hello

I would like to ask an question connected with the theory:
What are the three address spaces supported by Pentium in the protected-mode?

Please help

10x all
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Steven_T_Intel
Employee
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Your question is very similar to an assignment in the book

Introduction to Assembly Language Programming: For Pentium and RISC Processors

By Sivarama P. Dandamudi

The exercise appears on page 65 and is exercise 3-2.


It also appears in the book

Fundamentals of Computer Organization and Design

By Sivarama P. Dandamudi

This exercise is on page 271 and is exercise 7-2.
You can go to http://www.intel.com/support/processors/sb/CS-001498.htm to see the following:
What Mode of Addressing do the Intel Processors Use?

Symptom(s):

  • Address mode
  • Protected mode
  • Real mode
  • SMM mode
  • Virtual 8088 mode

Solution:
Intel processors since the Intel386 processor can run one of three modes. They are the Real mode, Protected mode and SMM mode. You can also add a forth mode called Virtual 8088 mode, which is considered a pseudo mode of the protected mode. When the processor starts booting the computer, the processor starts in real mode where it operates like a 8086 processor that can see up to 1 MB of RAM. The native mode for the processor is the Protected mode which it will switch into while it loads Windows* or some other advanced operating system. While in protected mode, the processor uses segmented (non-linear) addressing, as opposed to linear addressing. Segmented addressing means that memory (physical memory and virtual memory) is divided into 64K blocks. This is the maximum value for the Instruction Pointer (IP) register. The IP register works with the Code Segment (CS) register to point to the memory location from where the microprocessor should fetch its next instruction. The IP uses 4 bytes for memory addressing, therefore making 0FFFFH the maximum memory location (0FFFFH = 64K). For more information, refer to the Intel Architecture Software Developer's Manual - Volume 1: Basic Architecture.

This applies to:
Dual-Core Intel Xeon Processor 7000 Sequence
Intel Celeron Processor Family
Intel Core Duo Processor
Intel Core Solo processor
Intel Core2 Duo Desktop Processor
Intel Core2 Duo Mobile Processor
Intel Core2 Extreme Processor
Intel Pentium 4 Processor
Intel Pentium 4 Processor Extreme Edition
Intel Pentium D Processor
Intel Pentium III Processor
Intel Pentium III Xeon Processor
Intel Pentium M Processor
Intel Pentium Processor Extreme Edition
Intel Xeon Processor
Mobile Intel Celeron Processors
Mobile Intel Pentium 4 Processors - M
Mobile Intel Pentium III Processors
Multi-Core Intel Xeon Processor 3000 Sequence
Multi-Core Intel Xeon Processor 5000 Sequence


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johnsecada
Beginner
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I'm not shure and I want ot ask am I on the right way.
I think that the address spaces in protected mode are:
- I/O address space
- non-linear addressing space (segmetated, logical address space)
- linear address space (pagin traslation to phisical address, if no paging then linear = physical address)

Please tell me because i am not sure about my conclusion
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Steven_T_Intel
Employee
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The CPU uses two address spaces: I/O tocontrol devices on I/O ports, and Memory forROM, DRAM, MMIOtransactions. You may have a third mixed in there called Config space which is used to configure your PCI bus devices.
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