Basic Method

• Users prefer to view memory as a collection of variable-sized segments, with no necessary ordering among segments (Figure 8.18).

  Figure 11: User's view of a program.

  
• Consider how you think of a program when you are writing it. You think of it as a main program with a set of methods, procedures, or functions.
• Segmentation is a memory-management scheme that supports this user view of memory. A logical address space is a collection of segments.
• Each segment has a name and a length. The addresses specify both the segment name and the offset within the segment.
• The user therefore specifies each address by two quantities:
  • a segment name
  • an offset
• For simplicity of implementation, segments are numbered and are referred to by a segment number, rather than by a segment name.
• Thus, a logical address consists of a two tuple:

  <segment-number, offset>