IMPLEMENTATION OF SEGMENTATION WITH AN EXAMPLE

Segmentation is a memory-management scheme that represents the user view of memory. A logical address space is the collection of segments. Every segment has a name and a length. The addresses specify both the offset and the segment name within the segment. The user thus specifies each address by two quantities: an offset and a segment name. For the simplicity of execution, the segments are numbered and are referred to by a segment number, relatively than by a segment name. Therefore, the logical address consists of a two tuple segment-number offset   

Execution is defined to map two-dimensional user-defined addresses into one-dimensional physical addresses. This mapping is distressed by segment table. Every entry in the segment table has a segment limit and a segment base. The segment base holds the starting address where the segment resides in memory, while the segment limit specifies the length of the segment.

A logical address consists of two parts an offset and a segment number, s, into that segment d. The segment number is utilized as an index to the table. The offset d of the logical address should be between 0 and the segment limit. The segment table is basically an array of base-limit register pairs.