The document discusses RAM and ROM memory. RAM (random access memory) is the main memory of a computer system, used to temporarily store data and instructions. It is volatile memory that allows reading and writing. ROM (read only memory) is permanent memory where instructions cannot be changed; it is used to store basic input/output functions. The document outlines the structure of memory chips and different types of RAM like DRAM and SRAM and ROM.

2. Topic : Ram & Rom
Lecturer : Dr. Syed Sherjeel Gillani

3. Presented By:
• Mr. Qasim Ali 22772
• Mr. Zamama Zaman 22699

4. Topic :
• Main memory.
• Structure of main memory.
• Types of main memory.
• What is Ram & Rom.
• Types of ram & rom.
• Digital logical circuit of ram & rom.

5. Main Memory :
• Directly attached on CPU and install on mother board .
• Used to store data program and data that are being used.
• Known as working area of computer system.
• Computer cannot work with out main memory.
•

6. Structure Of Main Memory
• Main memory is built in a form of chip.
• Chip is made of a semi conductor material.
• The chip consist of thousand of million of cells.
• Each cell can store one bit i.e. 0 and 1.
• The cell in the main memory are logically organized as groups of 8 bits.
• Each byte is assigned a unique number.
• This number is known as the address of the byte.
• Main Memory has two types RAM & ROM.

7. RAM(random access memory)
• Also called direct memory.
• RAM is used to store data and instructions temporarily.
• RAM is volatile memory.
• RAM is read write/memory.
• CPU can read data from RAM and write data to RAM.
• It is used to store data and instruction.
• RAM is also called main memory or primary storage.

9. Types of RAM:
• DRAM(dynamic random access memory).
• Slower
• Loss expensive
• Utilize more power
• Capacitor storage cells
• Must be refreshed
• Used as main memory

10. SRAM(static random access memory)
• Faster
• More expensive
• utilizes less power
• It does not need to be power-refreshed
• Used as Cache memory
• Flip-flop storage cells

11. How RAM work

13. Rom(Read only memory)
• Rom is permanent memory.
• The instructions written in ROM cannot be changed or deleted.
• It is not possible to write new information or instructions in ROM.
• ROM is non-volatile memory.
• The instructions are written into ROM at manufacturing time.

14. Type of ROM:

15. ROM BLOCK DIAGRAM
• Figure show a 16x8 ROM.
• 4 address input and 8 data outputs.
• CS: Chip Select.
• The Read operator.

18. RAM vs ROM