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 On Time RTOS-32 Documentation
 Welcome
 RTTarget-32
RTTarget-32 Programming Manual
 Introduction
Running Win32 Programs without Win32
The i386 Microprocessor
 Real Address Mode
Virtual 8086 Mode
Protected Mode
16-Bit Protected Mode
32-Bit Protected Mode
Descriptors and Descriptor Tables
Privilege Levels
Paging
Virtual, Linear, and Physical Addresses
Exceptions and Interrupts
RTLoc: Locating a Program
Running a Program on the Target
Cross Debugging
Using an IDE
The RTTarget-32 API
Demo Programs
Advanced Topics
Compiling and Linking with On Time RTOS-32
Redistributable Components of RTTarget-32
RTLoc Error Messages
RTTarget-32 Reference Manual
RTKernel-32
RTFiles-32
RTIP-32
RTPEG-32
RTUSB-32
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16-Bit Protected Mode
This is the only protected mode available on 80286 processors. Segments can have any length between 1 and 216 = 64 kilobytes. A segment base has 24 bits on an 80286 CPU, limiting the available address space to 16 megabytes. On 386 and higher CPUs, a segment base can have 32 bits. Thus, even in 16-bit protected mode, the complete 32-bit address space of 4 gigabytes is available (although many segments are required to use the complete address space).
Near pointers are 16-bit offsets interpreted relative to a segment register. Far pointers consist of a 16-bit selector and a 16-bit offset.
 Protected Mode
 32-Bit Protected Mode
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