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Need ECC [256 bytes / One bit fix / Detect 2bit Error] Sourc

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year

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one bit error

Does anybody give me ECC source code as follows.

- 256 Bytes

- Fix One Bit

- Detct Two Bit Error
 

dainis

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ecc-256

look ECC links:
h**p://w*w.csl.sony.co.jp/person/morelos/ecc/codes.html
h**p://w#w.iet.unipi.it/~luigi/fec.html
h**p://w#w331.jpl.nasa.gov/public/JPLtcodes.html
h**p://w*w.ece.wpi.edu/courses/ee535/hwk97/hwk4cd97/bad/paper.html
h**p://rscode.sourceforge.net/
h**p://w*w.4i2i.com/reed_solomon_software.htm
h**p://co-optic.com/reedsolm.htm
h**p://w*w.sworld.com.au/links.html
h**p://w#w.radiodesign.com/rs_sale.htm
h**p://###.itr.unisa.edu.au/tech_res/tech_res.html
h**p://###.tcs.hut.fi/~helger/crypto/link/coding_theory/index.htm
h**p://kom.auc.dk/~heb/kurser/ercon

h**p//citeseer.nj.nec.com/cs?q=error+control+coding&cs=1
 

year

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512 byte ecc source

Thanks for your help.
I will check...
 

yager

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ecc sample source code for 512 byte

The SMC/NAND Flash is used ECC to detect/correct error as your request.
To get more details please visit:
SSFDC Forum: http://www.ssfdc.or.jp/english/index.htm
Samsung Semiconductor
http://www.samsungelectronics.com/s..._data/application_notes/application_notes.htm

Yes, it is hamming code as the C-Man pointed out.
If you check Samsung's sample code,
you will find it is not good implemation for performance and code size.
So I built the pre-calculated table to improve it such like CRC table.
The code is snipped out of mine (In fact, I used 512 bytes/24 bits ECC
for SMC/NAND Flash, not 256 bytes/22 bits ECC)
but I think it should be working well.
Sorry just a bit of comment in code, if you'd like to know more details,
you have to read the documents which dainis and C-Man posted on.

The attachment is a sample code to implement it.
FYR
 

year

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ecc source

Hello Yager,

It is very helpful for me.

I will put it into my sorce and test.

Thanks a lot.
 

year

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bit error level samsung fix

Hello Yager,

It is very helpful for me.

I have tested it.

One bit error can be fix: OK

Two bit error is detected : OK

But more bits are not exact.

(Source is limited to two bits as my test.....)

Does anybody try to test this ?
(Three or Four bit error........)
 

barny

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ecc flash samsung c code

year said:
Hello Yager,

It is very helpful for me.

I have tested it.

One bit error can be fix: OK

Two bit error is detected : OK

But more bits are not exact.

(Source is limited to two bits as my test.....)

Does anybody try to test this ?
(Three or Four bit error........)
The reason people choose a Hamming code is that it's simple (i.e. easy to implement), and very effective in a situation where:
a) 1-bit errors are most common, 2-bit less, 3-bit (and more) effectively non-existent
b) You accept that if more than two errors occur, you are stuffed, but by (a), this is very very rare.

So, if you put more than 2 errors into Hamming-protected data, it will either a) tell you (wrongly) the data is OK, or b) correct (wrongly) only one bit (probably the wrong one) and tell you everything is OK, or c) warn (incorrectly but usefully) that 2 bits are corrupt.

You could use a different scheme which gives more protection, but this will impose correspondingly more overhead on efficiency, because more protection bits are needed and more processing is needed to detect/correct errors.

However, exactly the same applies to any FEC (forward Error Correction) scheme, just with different levels for bit errors corrected, bits errors detected, and errors spuriously ignored/corrected/reported.

As in most things in life, you get what you pay for; put in lots of protection bits and processor power and you will get better protection. Note, however, that no scheme over a lossy channel can *guarantee* perfect data transmission, although with bidirectional channel (like TCP/IP) you can get pretty good quality even over poor connections.

HTH
barny
 

year

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ecc bit dected

Hello barny,

As my test, I could observe one bit error someimes and 2bit error is long term test result.

3 bit eor is made by me to confirm source code.

Now I can unserstand my test result because of you.

Thanks a lot.
 

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