memory of computer ram rom ddr sdram etc.

1. MEMORY
BY :- ER. ANAND TIWARI

2. INTRODUCTION
Memory is one of the functions of the brain that enables to
store and remember the past events.
Similarly in computer the term memory refers to a chip that
stores data.
The processor retrieves information stored in the memory
for processing.

3. MEMORY SPECIFICATION
• Memory is selected for the system depending on its motherboard
configuration.
• The different memory characterstics are :
1. Number of Pins
2. Memory Frequency
3. Single or Dual Channel memory

4. DDR3
4GB
1600
MHz
Frequenc
y
Transcend Make

5. NUMBER OF PINS
Each RAM has certain number of PINS or connectors using
which RAM communicates with the processor through RAM
slots.

6. SINGLE CHANNEL MEMORY
• Commonly all kinds of memory devices are 64 bit device i.e. 64
wires connecting the memory controller and memory sockets.

7. DUAL CHANNEL MEMORY

8. TYPES OF MEMORY
Volatile Memory Non Volatile Memory
 It loses the data as
soon as the power
supply is turned off.
 It does not loses the data
as soon as the power
supply is turned off.

9. • Further , memory is classified into physical , flash and cache
memory .
• Physical Memory :-
Physical memory is the total amount of memory
installed in the computer .there are two types of physical memory
are:-
1. RAM (Random Access Memory)-Temporary store data
2. ROM (Read Only Memory)-Permanently store data

10. TYPES OF ROM
• PROM(Programmable Read Only Memory) :- using higher
voltage for store data.
• EPROM(Erasable Programmable Read Only Memory) :- UV
rays can remove the program from this memory .
• EEPROM/Flash ROM :- Electrical ErasablePROM using
Electrical signal removes the program from the memory.

11. FLASH MEMORY
• Flash memory is the high density device.
• It is non-volatile memory , fast reading and writing the data.
• Is is an electricall re-programmable device.
• Ex:-MMC(multimedia card) ,SD(Secure Digital) , Compact
Flash , Memory Stick .

12. CACHE MEMORY
• Cache memory is a small and fast memory which is placed
between the CPU and main memory.
• It will first access the cache to find the data .

13. TYPES OF RAM
SRAM
(static random
access memory)
DRAM
(dynamic random
access memory)

14. SRAM
• Stores data till the power is supplied
• Uses an array of 6 transistor for each memory cell
• Does not refreshes the memory cell after each reading of the
transistor
• Data access is faster
• Consumes more power
• Low density//less memory per chip .
• Cost per bit is high.

15. DRAM
• Stores data only for few milliseconds even when power is supplied
• Uses a single transistor for each memory cell
• Need refresh the memory cell after each reading of the capacitor
• Data access is slower
• Consumes less power
• High density/more memory per chip .
• Cost per bit is low.

16. TYPES OF DRAM
SDRAM RDRAM DDR1 RAM DDR2 RAMDDR2 RAM

17. • Synchronous Dynamic Random Access Memory
• no of pins :- 168
• Operating voltage :- 3.3 volts
• Frequency :- 133 MHz

18. RDRAM
• Rambus Dynamic Random Access Memory
• no of pins :- 160 or 184
• Operating voltage :- 3.3 volts
• Frequency :- 300 – 400 MHz

19. DDR / DDR1 RAM
• Stands for DOUBLE DATA RATE RAM
• No. of PINS:- 184
• Operating Voltage :- 2.5 volts
• Frequency / data rate :- 266 – 400 MHz.
• Thermal Sensor :- No

20. DDR2 RAM
• Stands for DOUBLE DATA RATE2 RAM
• No. of PINS:- 240
• Operating Voltage :- 1.8 volts
• Frequency / data rate :- 533 – 800 MHz.
• Thermal Sensor :- No

21. DDR3 RAM
• Stands for DOUBLE DATA RATE2 RAM
• No. of PINS:- 240
• Operating Voltage :- 1.8 volts
• Frequency / data rate :- 533 – 800 MHz.
• Thermal Sensor :- No

22. RDRAM
Two notches