Direct mapping cache pdf

Block j of main memory will map to line number j mod number of cache lines of the cache. An address in block 0 of main memory maps to set 0 of the cache. Direct mapping map cache and main memory break the. You will calculate the miss rate for the following code using this cache. Following diagram shows how the address is divided. Memory locations 0, 4, 8 and 12 all map to cache block 0. No replacement policy necessary access pattern may leave empty slots in. How many bits are in the tag, line and offset fields. Chapter 4 cache memory computer organization and architecture. Mapping function direct, assoociative, set associative.

Cache addresses cache size mapping function direct mapping associative mapping setassociative mapping replacement algorithms write policy line size number of caches luis tarrataca chapter 4 cache memory 3 159. Adapted from computer organization and design, 4thedition, patterson and hennessy. To understand the mapping of memory addresses onto cache blocks. Directmapped and set associative caches eecs instructional. Consider a direct mapped cache of size 64k with block size of 16 bytes. Pdf hardware techniques for improving the performance of caches are presented. Take advantageadvantage ofof thethe principleprinciple ofof localitylocality toto presentpresent thethe useruser with as much memory as is available in the cheapest. Direct mapping cache practice problems gate vidyalay. Direct mapped eheac h memory bl kblock is mapped to exactly one bl kblock in the cache lots of lower level blocks must share blocks in the cache address mapping to answer q2. Write the appropriate formula below filled in for value of n, etc. Directmapped caches, set associative caches, cache. Draw the cache and show the final contents of the cache as always, show your work. Direct mapping address structure tag line or slot word t s w cache line size determines how many bits in word field ex.

In this a given main memory block can be placed in one and. Pdf improving directmapped cache performance by the addition. The tasks required of the direct mapped cache in servicing a memory request. Table of contents ii multilevel caches unified versus split caches. A direct mapped cache has one block in each set, so it is organized into s b sets. For a direct mapped cache with 2n blocks, n bits are used for the index. For example, on the right is a 16byte main memory and a 4byte cache four 1byte blocks. Each memory block is mapped to exactly one slot in the cache directmapped. Miss caching places a small, fully associative cache between a cache. Directmapped caches, set associative caches, cache performance. Intermediate level between cpu and memory inbetween in size, cost, and speed memory hierarchy, organization, structures set up to exploit temporal and spatial locality.