16. Memory Management

16.3 Virtual Address Translation

Programs can operate using either physical or virtual memory addresses:

physical addresses correspond to hardware locations in main memory

virtual addresses are logical values only, and do not correspond to fixed hardware locations

Virtual addresses must first be translated (finding the physical address at which the virtual address points) before main memory can be accessed. This translation is essential for multitasking computer systems, because it allows the operating system to load programs anywhere in main memory independent of the logical addresses used by the programs.

This translation also implements a memory protection scheme, which limits the amount of memory each program may access. The scheme prevents programs from interfering with the memory used by other programs or the operating system.

Copyright 1995, MIPS Technologies, Inc. -- 29 JAN 96

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