Why don’t use flash memory to design smart card IC?

Usually Smart Card IC uses EEPROM as non-volatile memory. Recently a few Smart Card IC design company uses Flash memory instead of EEPROM. Flash has better performance than EEPROM, and has lower cost. Why don’t majority company use flash memory to design smart card IC?

EEprom can be written to many more times than Flash. Remember that these cards usually have a lifetime of a few years, could be thousands of writes in that time. Flash usually limited to around 1000. This may not be the only reason, just guessing here

Re: Why don’t use flash memory to design smart ca

Can you tell me what is the difference in the technique of fabrication between EEPROM and FLASH memories ?

I did just that!

Hi guys ..

I did a designa of a very , very smart card 2 years ago . I had 8 megs of flash and a cygnal cpu (25 mips) it was basically a server wih an OS and file system . It had a TCP/IP stack and a triple DES encription ..

The whole concept is very innovative . because it uses an external server .
SOMPLEPLACE in the WORLD to VERIFY the identity of the card bearer .

The design is now in legal BATTLE with one of my partners ...
I think that that's the ultimate card ..

If some one one to temper with the card it erases itself!

If you use it as a credit card . automatically sends you a copy of your invoice to your e-mail.

Now, Flash has more than 100K erase/write cycles. It seems that write time is not question.

Re: Why don’t use flash memory to design smart ca

This document relates to ST Flash and their micros but may give you an insite into the differant technologies.

Regards
NTFreak

There are many kinds of Flash, such as NAND ,NOR type . What's the difference?

Have a look at the following doc:
h**p://***.semicon.toshiba.co.jp/eng/prd/memory/pdf/nandflash_what_e.pdf

Regards
NTFreak

Thank you !
What's differrence of their application?

Nor have higher cost and most of them use in up code and Nand have its nature with small area thus result in larger size and most of them use in data storage device . Only 2 majory vendor provide the nane flash due to the patent issue . They are samsung and toshiba . The density have been reach 8Gbits now and day . All DSC card(xd/sd/mmc/cf/ms/sm) build inside with nand flash .

There are two primary flash technologies — NOR and NAND technologies — whose names are derived from the type of semiconductor logic used to implement flash memory structures.
The NOR technology is featured in Intel and AMD flash memory devices. It features highspeed,
random access to bit storage and low error rates, but offers less density than
NAND flash technology. It has high endurance—that is, it can reliably support up to one
million program/erase cycles without requiring error correction.
NAND technology ties a string of 16 or 32 single-bit-storage transistors together. This
structure reduces the number of memory array contacts and allows greater density. The
trade-offs involved with implementing this structure are 1) data cells must accessed
sequentially, and 2) read and write errors are more prevalent. As a result, NAND devices
require error correction

Why doesn't anyone mention the new FRAM technology?
FRAM is superior to both EEPROM and FLASH. FRAM writie speed is more than 100.000 times faster than FLASH and EEPROM write speed.
You can already get FRAM's for direct hardware replacement for EEPROM's: http://www.ramtron.com/products/producthome.htm
FRAM might replace both EEPROM, FLASH, DRAM, SRAM and other memory types in near future.

Here are som links to FRAM and comparisons between FRAM and other memory types:

**broken link removed**
FRAM (Ferroelectric Random Access Memory) is a non-volatile memory combining both ROM and RAM advantages in addition to non-volatility features. Its higher speed in write mode, its lower power consumption as well as its higher endurance, make FRAM superior to any other memory type. As a high-speed non-volatile memory, FRAM can be used in the wide range of offerings.

**broken link removed**

http://www.ramtron.com/press/pressfaq.htm

http://www.nvtech.com.au/

**broken link removed**

**broken link removed**

FRAM is manufactured more and more difficulty than EEPROM or Flash.

The smart card is probably one of the most demanding environments for an Integrated
Circuit (IC), also referred to as a chip. Smart card ICs have critical size, speed, power
consumption, cycling endurance, data retention, and cost restraints.
The chip must be small enough so that the chip will not break if the card is bent during
the card’s three year lifetime. The processor must read and write information to the
memory arrays without slowing down human interactions, and without drawing too
much power from the terminal. The chip must retain the information when the smart
card is removed from the terminal. The memory arrays must be able to be erased and
re-programmed with new data many times during the life of the card. And the cost must
not prohibit mass distribution. There are many different types of memory that are used
to meet these constraints.
· Masked Read Only Memory (ROM) and EEPROM
Masked ROM is the oldest technology, having been in use for over thirty years.
Electrically Erasable Programmable Read Only Memory (EEPROM) was
developed to overcome the inflexibility of masked ROM, and is used to store
code updates and data. Masked ROM and EEPROM are regularly used
together on the same chip.
· Flash
Flash memory is a modern, efficient re-design of the EEPROM memory cell.
Flash can be designed as One-Time Programmable Read Only Memory
(OTPROM) in place of masked ROM, and also act as regular EEPROM
· Ferroelectric Random Access Memory (FeRAM)
FeRAM is a relatively new technology that is not yet in widespread use so will
not be discussed in any great detail, however Ferroelectric memory designs
and volume manufacturing technologies are still advancing.

May be security issue is the most concern .
But actually I do not know is the EEPROM more secure than FLASH regarding information retrieval .

At lease Flash is the same secure as EEPROM