Flash Memory Recoverd

8/14/2019 Flash Memory Recoverd

1/40

1

FLASHFLASHMEMORYMEMORY

Lakshika Somani3rd yr.

Electronics & Communication


2/40

2

ContentsContents

Memory

Flash memory

Flash memory as a solidstate storage device

Examples of Flash memory

Flash Memory Basics

Flash Memory: Tunneling and Erasing

Removable Flash Memory Cards

Flash memory v/s hard disk

Smart media

Compact Flash

Memory Standards

Applications of Flash Memory


3/40

3

MemoryMemory


4/40

4

Flash memoryFlash memory Flash memory is a form of EEPROM that allows

multiple memory locations to be erased or writtenin one programming operation. The EEPROM isused due to the disadvantage of EPROM in which

the memory must be removed from the boardand placed in an EPROM programmer forprogramming and erasure procedure. Flashmemory is a nonvolatile memory using NORtechnology, which allows the user to electrically

program and erase information.


5/40

5

Flash memory as a solidFlash memory as a solidstate storage devicestate storage device

Electronic memory comes in a variety of forms toserve a variety of purposes. Flash memory isused for easy and fast information storage in

such devices as digital cameras and homevideo game consoles. It is used more as ahard drive than as RAM. In fact, Flash memory isconsidered a solid state storage device.

Solid state means that there are no moving parts,everything is electronic instead of mechanical.
http://electronics.howstuffworks.com/digital-camera.htmhttp://electronics.howstuffworks.com/video-game.htmhttp://computer.howstuffworks.com/hard-disk.htmhttp://computer.howstuffworks.com/ram.htmhttp://computer.howstuffworks.com/ram.htmhttp://computer.howstuffworks.com/hard-disk.htmhttp://electronics.howstuffworks.com/video-game.htmhttp://electronics.howstuffworks.com/digital-camera.htm


6/40

6

Examples of Flash memoryExamples of Flash memory Our computer's BIOS chip Compact Flash (most often found in digital

cameras)

Smart Media (most often found in digital

cameras) Memory Stick (most often found in digital

cameras)

PCMCIA Type I and Type II memory cards

(used as solid-state disks in laptops) Memory cards for video game consoles


7/40

7


8/40

8

Flash Memory BasicsFlash Memory Basics

Flash memory is a type ofEEPROM chip. It has agrid of columns and rows with a cell that has twotransistors at each intersection

The two transistors are separated from each otherby a thin oxide layer. One of the transistors isknown as a floating gate, and the other one isthe control gate. The floating gate's only link to

the row, or word line, is through the controlgate. As long as this link is in place, the cell has avalue of 1. To change the value to a 0 requires acurious process called Fowler-Nordheimtunneling.


9/40

9


10/40

10

Flash Memory: TunnelingFlash Memory: Tunnelingand Erasingand Erasing

Tunneling is used to alter the placement ofelectrons in the floating gate. An electrical charge,usually 10 to 13 volts, is applied to the floatinggate. The charge comes from the column, or bit

line, enters the floating gate and drains to aground.

This charge causes the floating-gate transistor toact like an electron gun. The excited electrons are

pushed through and trapped on other side of thethin oxide layer, giving it a negative charge. Thesenegatively charged electrons act as a barrierbetween the control gate and the floating gate.
http://electronics.howstuffworks.com/digital-electronics.htmhttp://electronics.howstuffworks.com/question694.htmhttp://electronics.howstuffworks.com/question694.htmhttp://electronics.howstuffworks.com/digital-electronics.htm


11/40

11


12/40

12


13/40

13

A special device called a cell sensormonitors the level of the chargepassing through the floating gate. If theflow through the gate is greater than

50 percent of the charge, it has a valueof 1. When the charge passing throughdrops below the 50-percent threshold,the value changes to 0. A blank

EEPROM has all of the gates fully open,giving each cell a value of 1.


14/40

14

The electrons in the cells of a Flash-memory chip can be returned to normal("1") by the application of an electricfield, a higher-voltage charge. Flashmemory uses in-circuit wiring to applythe electric field either to the entire chipor to predetermined sections known asblocks. This erases the targeted area ofthe chip, which can then be rewritten.Flash memory works much faster thantraditional EEPROMs because instead of

erasing one byte at a time, it erases ablock or the entire chip, and thenrewrites it.
http://computer.howstuffworks.com/bytes.htmhttp://computer.howstuffworks.com/bytes.htm


15/40

15

You may think that your car radio hasFlash memory, since you are able toprogram the presets and the radio

remembers them. But it is actuallyusing Flash RAM. The difference is thatFlash RAM has to have some power tomaintain its contents, while Flashmemory will maintain its data withoutany external source of power. Eventhough you have turned the power off,the car radio is pulling a tiny amount ofcurrent to preserve the data in the

Flash RAM. That is why the radio willlose its presets if your car battery diesor the wires are disconnected.
http://electronics.howstuffworks.com/radio.htmhttp://computer.howstuffworks.com/ram.htmhttp://electronics.howstuffworks.com/battery.htmhttp://electronics.howstuffworks.com/wfc.htmhttp://electronics.howstuffworks.com/wfc.htmhttp://electronics.howstuffworks.com/battery.htmhttp://computer.howstuffworks.com/ram.htmhttp://electronics.howstuffworks.com/radio.htm


16/40

16

Removable Flash Memory CardsRemovable Flash Memory Cards

While your computer's BIOS chip is the most common form

of Flash memory, removable solid-state storage devices are

becoming increasingly popular. Smart Media and Compact

Flash cards are both well-known, especially as "electronic

film" for digital cameras. Other removable Flash memory

products include Sony's Memory Stick, PCMCIA memory

cards, and memory cards for video game systems such as

Nintendo's N64, Sega's Dreamcast and Sony's PlayStation.

We will focus on Smart Media and Compact Flash, but theessential idea is the same for all of these products. Every

one of them is simply a form of Flash memory.
http://electronics.howstuffworks.com/bios.htmhttp://electronics.howstuffworks.com/video-game.htmhttp://electronics.howstuffworks.com/n64.htmhttp://electronics.howstuffworks.com/dreamcast.htmhttp://electronics.howstuffworks.com/playstation.htmhttp://electronics.howstuffworks.com/playstation.htmhttp://electronics.howstuffworks.com/dreamcast.htmhttp://electronics.howstuffworks.com/n64.htmhttp://electronics.howstuffworks.com/video-game.htmhttp://electronics.howstuffworks.com/bios.htm


17/40

17

A Sony memory stick.A Sony memory stick.


18/40

18


19/40

19

Flash memory v/s hard diskFlash memory v/s hard disk

Flash memory is noiseless. It allows faster access.

It is smaller in size. It is lighter. It has no moving parts.

It can plug into anycomputer with a USB drive.


20/40

20

So why don't we just use FlashSo why don't we just use Flash

memory for everything?memory for everything?

Because the cost per megabyte for ahard disk is drastically cheaper, andthe capacity is substantially more.


21/40

21

Smart mediaSmart media The solid-state floppy-disk

card (SSFDC), better knownas Smart Media, wasoriginally developed byToshiba.

Smart Media cards areavailable in capacitiesranging from 2 MB to 128MB. The card itself is quitesmall, approximately 45 mm

long, 37 mm wide and lessthan 1 mm thick. This isamazing when you considerwhat is packed into such atiny package!

.


22/40

22

Smart Media cards are elegant in their simplicity.A plane electrode is connected to the Flash-memory chip by bonding wires. The Flash-memory chip, plane electrode and bonding wiresare embedded in a resin using a technique calledover-molded thin package (OMTP). This allowseverything to be integrated into a single packagewithout the need for soldering


23/40

23

The OMTP module is glued to a basecard to create the actual card. Powerand data is carried by the electrodeto the Flash-memory chip when thecard is inserted into a device. Anotched corner indicates the power

requirements of the Smart Mediacard. Looking at the card with theelectrode facing up, if the notch is onthe left side, the card needs 5 volts.

If the notch is on the right side, itrequires 3.3 volts.


24/40

24

Smart media cardSmart media card


25/40

25

Smart Media cards erase, write and

read memory in small blocks (256- or512-byte increments). This approachmeans that they are capable of fast,reliable performance while allowing

you to specify which data you wish tokeep. They are small, lightweight andeasy to use. They are less ruggedthan other forms of removable solid-state storage, so you should be verycareful when handling and storingthem.


26/40

26

Compact FlashCompact Flash

Compact Flash cards were developed bySandisk in 1994, and they are differentfrom Smart Media cards in two important

ways:

They are thicker.

They utilize a controller chip.


27/40

27


28/40

28

Compact Flash consists of a smallcircuit board with Flash-memory

chips and a dedicated controllerchip, all encased in a rugged shellthat is several times thicker than aSmart Media card.

Compact Flash cards are 43 mmwide and 36 mm long, and come intwo thicknesses: Type I cards are3.3 mm thick, and Type II cards

are 5.5 mm thick.


29/40

29

Compact Flash cardCompact Flash card


30/40

30


31/40

31


32/40

32


33/40

33

Compact Flash cardCompact Flash card

Compact Flash cards support dual voltageand will operate at either 3.3 volts or 5volts.

The increased thickness of the card allowsfor greater storage capacity than SmartMedia cards. Compact Flash sizes rangefrom 8 MB to 6GB. The onboard controllercan increase performance, particularly ondevices that have slow processors. Thecase and controller chip add size, weightand complexity to the Compact Flash cardwhen compared to the Smart Media card.


34/40


35/40

35

Card ReaderCard Reader


36/40

36

Internal Card ReadersInternal Card Readers


37/40

37

Applications ofApplications of

Flash MemoryFlash Memory

The Flash Memory technology hasevolved into the preferred storagemedia for a variety of consumer andindustrial devices.


38/40

38

IN CONSUMER DEVICES, FLASHIN CONSUMER DEVICES, FLASHMEMORY IS WIDELY USED INMEMORY IS WIDELY USED IN

Notebook computers

Digital cameras

Personal Digital Assistants (PDAs)

Cell phones Global Positioning Systems (GPS)

Electronic musical instruments

Solid-state music players such as

Television set-top boxes

MP3 players Pagers

Personal computers


39/40

39

IN INDUSTRIAL DEVICES, FLASHIN INDUSTRIAL DEVICES, FLASHMEMORY IS WIDELY USED INMEMORY IS WIDELY USED IN

Security systems

Military systems

Embedded computers

Solid-state disk drives Networking and communication products

Wireless communication devices

Retail management products (e.g., handheld

scanners) Medical products


40/40

40

Thank youThank you

Documents

Flash Memory Recoverd