memory

1. Memory Farhana Rahman December 7th , 2004 CS147, SECTION 3

2. Outline Memory Hierarchy Addressing Modes Architecture Types of Memory

3. Memory Hierarchy Memory refers to any storage medium used for storing information. Since there are many different kinds of storage media , we can categorize them according to the memory speed.The memory hierarchy is as follows: Cache Memory Secondary memory Main (primary) memory Archival memory

4. Memory Characteristics

5. Definition Cache Memory: The cache memory is a small section of memory that is usually placed between the processor and the main memory and is used when the main memory speed is much slower than the processor speed. Main (Primary) Memory: The main memory contains the primary storage space, which is randomly accessible by the processor.The primary function of the main memory is to store the instructions and data necessary for the current execution of the processor.

6. Secondary Memory: The information stored in the main memory is not easily accessible to the programmer and is not suited for storing a lot of information. Secondary storage media are useful for this purpose. Archival Memory: Archival memory refers to permanent storage media.This include media such as cards and paper printouts. Their use is strictly for the programmer to store computation results. Definition

7. In order to access the memory, an address must be provided.The manner in which the address is specified in an instruction is called the addressing mode. Addressing modes can be categorized into: Basic addressing modes Special addressing modes Addressing Modes

8. Basic Addressing Modes

9. Basic Addressing Modes

10. Basic Addressing Modes

11. Basic Addressing Modes

12. Special Addressing Modes

13. Special Addressing Modes

14. Special Addressing Modes

15. Virtual Memory

16. Memory System Architecture

17. Memory Cells The memory cell is a simple flip-flop or a bistable multivibrator that can be found in one of two stable states: an ON state and an OFF state. Memory components are composed of three major parts: the memory cells, the row decoder, and the column decoder.

18. Memory Organization Memory organization is usually given in terms of the number of individually accessible or addressable words in the chip and the word length. Bit �Slice Organization: The concept of bit-slice organization is to have many chips operating together in parallel, each responsible for the operations within a thin slice (a few bits) of the word.

19. Memory Segmentation: Although the bit-slice organization technique provides the necessary tools for the design of a memory system with any width, the memory segmentation technique gives the necessary tools for the design of a memory system with any depth. In memory segmentation, many memory chips are connected together to form the complete memory system. Memory Organization

20. Board/Bank Segmentation: Often only a fixed number of memory chips can fit into a specific size of circuit board. If more memory is required, multiple memory boards are used. The portion Of memory located on a particular board is called a memory bank. The total memory is composed of many memory banks. All banks are usually connected to a motherboard. Memory Organization