MEMORY ORGANIZATION (PART 1)

Assalamualaikum and Hello guys!

This post we will discuss about Cache Memory.

CACHE MEMORY 

• A typical computer program flows in a straight-line fashion with program loops and subroutine calls encountered frequently.
• If the active portions of the program and data are placed in a fast small memory,the average memory access time can be reduced.The memory known as Cache memory.
• The performance of cache memory is frequently measured in terms of a quantity called hit ratio.
• When the CPU refers to memory and finds the word in cache,its said to produce a hit.
• If the word is not found in cache,its in main memory and its counts as a miss.

CHARACTERISTIC of CACHE MEMORY

• It is fast access time.
• Mapping process is a transformation of data from main memory to cache memory.
• 3 types of mapping process are: 

  

    ASSOCIATIVE MAPPING 

The fastest and most flexible cache organization uses in associative memory.There have stores both the address and content (data) of the memory word.If the address is found corresponding data is read otherwise main memory is accessed for the word.This is expensive compared to random-access memories.

EXAMPLE FOR
ASSOCIATIVE MAPPING



DIRECT MAPPING

The direct mapping cache organization uses the n-bit address to access the main memory and the k-bit to access the cache.Each word in cache consists of the data word and associated tag.

EXAMPLE FOR
DIRECT MAPPING





SET- ASSOCIATIVE
MAPPING
In which each word of cache can store two or more words of memory under the same index address.Each data word is stored together with its tag and the number of tag-data items in one word of cache is said to form a set.

EXAMPLE FOR
SET-ASSOCIATIVE MAPPING

AHMAD AMNI FARHAN BIN MISHADI
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