ECC for Samsung nand flash

[Charles Manning]

On Tuesday 30 March 2004 17:22, Thomas Gleixner wrote:
> On Tuesday 30 March 2004 07:02, William J. Beksi wrote:
> > Has anyone implemented an ECC algorithm for Samsung nand flash devices?
> > The nand_ecc.c in the cvs seems to be specific for Toshiba devices.
>
> He ? What is specific ?
> ECC is a checksum algorithm for error detection and correction and is
> nowhere specific for Toshiba.

nand_ecc.c in mtd and yaffs_ecc.c in YAFFS implement exactly the same 
algorithm which is that specified by SmartMedia. Although nand_ecc.c was 
written by SJHill (then at Toshiba), the algorithm is identical to that in 
the application notes at Samsung.

The only differences between nand_ecc.c and yaffs_ecc.c are:
*yaffs_ecc.c is slightly faster (~15% - CPU dependent)
* yaffs_ecc.c provides two byte orders for storing the ECC.

At the end of the day, the ECC code is a software device and is in no way 
linked to the hardware. ie. the nand chip just blindly stores bytes.

-- Charles