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).

This applies to:

Intel® Celeron® Processor Family Intel® Core™ Duo Processor Intel® Core™ Solo processor Intel® Core™2 Duo Desktop Processor Intel® Core™2 Duo Mobile Processor Intel® Core™2 Extreme Processor Intel® Pentium® 4 Processor Extreme Edition Intel® Pentium® 4 Processors 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 Intel® Xeon® Processor 3000 Series Intel® Xeon® Processor 5000 Series Intel® Xeon® Processor 7000 Series Mobile Intel® Celeron® Processors Mobile Intel® Pentium® 4 Processors - M Mobile Intel® Pentium® III Processor