A Memory Management technique in which
memory is divided into variable sized chunks which can be allocated to
processes. Each chunk is called a Segment.
A table stores the information about
all such segments and is called Segment Table.
Segment Table: It
maps two dimensional Logical address into one dimensional Physical address.
It’s each table entry has
- Base Address: It contains the starting physical address where
the segments reside in memory.
- Limit: It specifies
the length of the segment.
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Translation of Two dimensional Logical Address to one
dimensional Physical Address.
Address generated by the CPU is
divided into:
- Segment number (s): Number of bits required to
represent the segment.
- Segment offset (d): Number of bits
required to represent the size of the segment.
Advantages of Segmentation:
- No Internal fragmentation.
- Segment Table consumes less space in comparison to Page table
in paging.
Disadvantage of Segmentation:
- As processes are loaded and removed from the memory, the free
memory space is broken into little pieces, causing External fragmentation.
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