This document discusses memory hierarchy and cache memory. It covers topics such as the differences between cache-main and main-secondary memory hierarchies, memory hierarchy with up to four levels where cost, access time, and storage capacity increase at each level, locality of reference both spatially and temporally, the structure and organization of cache memories including look aside and look through, basic read and write operations, the basic structure of a cache including direct-mapped and associative examples.

1. UNIT 5
MEMORY

2. Memory Hierarchy with two levels

3. Major Differences between cache-main and main-
secondary-memory hierarchies

4. Memory Hierarchy with three levels

5. Memory Hierarchy with four levels

6. • Cost per bit Ci>Ci+1
• Access time tAi<tAi+1
• Storage capacity Si<Si+1
Important Figure of merits

7. Locality of Reference-Spatial

8. Locality of Reference-Temporal

9. STRUCTURE OF A CACHE MEMORY

10. CACHE ORGANIZATION-LOOK ASIDE

11. CACHE ORGANIZATION-LOOK THROUGH

12. CACHE-READ OPERATION

13. CACHE-WRITE OPERATION

14. Basic structure of a cache

15. Structure of an associative (content addressable) memory

16. Associative memory cell: (a) logic circuit and (b) symbol

17. A 4 x 4-bit associative memory array

18. Direct-mapped cache with block capacity of two

19. Memory
Interfacing

20. A 256KB direct-mapped cache for a microprocessor