Different types of mappings used in cache memory - Computer architecture and design

What are the different types of mappings used in cache memory.

The three different types of mapping used for the purpose of cache memory are as follow, Associative mapping, Direct mapping and Set-Associative mapping.

- Associative mapping: In this type of mapping the associative memory is used to store content and addresses both of the memory word. This enables the placement of the any word at any place in the cache memory. It is considered to be the fastest and the most flexible mapping form.

- Direct mapping: In direct mapping the RAM is made use of to store data and some is stored in the cache. An address space is split into two parts index field and tag field. The cache is used to store the tag field whereas the rest is stored in the main memory. Direct mapping`s performance is directly proportional to the Hit ratio.

- Set-associative mapping: This form of mapping is a modified form of the direct mapping where the disadvantage of direct mapping is removed. Set-associative mapping allows that each word that is present in the cache can have two or more words in the main memory for the same index address.