This document provides an overview of computer memory. It discusses the different types of memory including internal processor memory, main memory, and secondary memory. Main memory includes RAM and ROM. RAM is further divided into DRAM and SRAM. ROM includes PROM, EPROM, EEPROM, flash ROM. The document also describes the memory hierarchy from fastest to slowest as registers, cache memory, main memory, and secondary storage. Cache memory is introduced between CPU and main memory to improve system performance.

1. COMPUTER MEMORY
COURSE INSTRUCTOR:
ASSOCIATE PROFESSOR DR. MOHAMMED NASIR UDDIN
PRESENTED BY
MD. RAFID ABRAR MIAH
16121021

2. INTRODUCTION
Computer memory is any physical device capable
of storing information temporarily or permanently.

3. MEMORY
Electronic components that store instructions, data, and
results
Consists of one or more chips on motherboard or other
circuit board
Each byte stored in unique location called an address,
similar to seats in a concert hall

4. MEMORY CAPACITY

5. CLASSIFICATION OF MEMORY
Memory
Internal
Processor
Memory
Main Memory
Secondary
Memory

6. INTERNAL PROCESSOR MEMORY
A small high speed memory inside the processor.
Temporary storage of instruction and data.
Example: Registers, built-in cache.

7. MAIN MEMORY
It is relatively large memory placed outside the
processor.
Data and instruction storage for the operation of the
processor.
Can be accessed directly and rapidly by the CPU.
Example: RAM, ROM

8. IMAGES OF MAIN MEMORY

9. TYPES
MAIN
MEMORY
RAM ROM

10. RANDOM ACCESS MEMORY
A temporary storage that can be read from or written into by
the user.
Volatile memory.
Every location can be accessed independently.
Access time for every location is constant and independent of
it’s position.
Two types of RAM-
RAM
Dynamic
RAM
Static
RAM

11. DYNAMIC RAM
DRAM stands for Dynamic RAM.
Relatively slower and low cost memory.
Used for main memory.
Contents are constantly refreshed 1000 times per
second
Access time 60 – 70 nanoseconds

12. TYPES

13. STATIC RAM
SRAM stands for static RAM.
Characterized by high speed and high cost.
Use six transistors to store data.
Access time 60 – 70 nanoseconds
Can accept one command and transfer one word of
data per clock cycle.

14. READ ONLY MEMORY (ROM)
A class of storage used in computer and other electronic
devices.
Data stored in it cannot be modified
Non-volatile memory.
In modern PCs, ROM is used to store the basic bootstrapping
firmware for the main processor, as well as the various firmware
needed to internally control self-contained devices such as
graphics card, hard disks, DVD drives, etc.

15. TYPES
ROM
Strict ROM
PROM
EPROM
EEPROM
EAROM
Flash ROM

16. SECONDARY MEMORY
Much larger in capacity but slower than main
memory.
Permanent storage of data and instruction.
Example: Hard disk, CD, Floppy etc.

17. MEMORY HIERARCHY
 In computer architecture the memory hierarchy is a concept used
to discuss performance issues in computer architectural design,
algorithm predictions, and lower level programming constructs
 Involving locality of reference. The memory hierarchy in computer
storage separates each of its levels based on response time.

19. Cache Memory
System performance suffers when processor waits for data
from slow memory device.
Cache memory is introduced between the CPU and the
main memory.
Cache is a high speed memory for holding recently
accessed data in main memory.
The amount of cache memory has a tremendous impact on
the computer's speed.

20. TWO TYPES OF CACHE MEMORY
 Level-1 L1 cache: CPU resident cache
 Level-2 L2 cache: Motherboard resident cache.

21. THE OPERATION OF CACHE MEMORY

22. AT A GALNCE

24. CONCLUSION
Memory is an important part of computer. Without
memory, Probably a computer is of no use is a
greater sense.