mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-05 02:51:00 +00:00
d4c8aa9cb4
Signed-off-by: Wolfgang Denk <wd@denx.de>
29 lines
1.1 KiB
Text
29 lines
1.1 KiB
Text
How to enable PMECC(Programmable Multibit ECC) for nand on Atmel SoCs
|
|
-----------------------------------------------------------
|
|
2012-08-22 Josh Wu <josh.wu@atmel.com>
|
|
|
|
The Programmable Multibit ECC (PMECC) controller is a programmable binary
|
|
BCH(Bose, Chaudhuri and Hocquenghem) encoder and decoder. This controller
|
|
can be used to support both SLC and MLC NAND Flash devices. It supports to
|
|
generate ECC to correct 2, 4, 8, 12 or 24 bits of error per sector (512 or
|
|
1024 bytes) of data.
|
|
|
|
Following Atmel AT91 products support PMECC.
|
|
- AT91SAM9X25, X35, G25, G15, G35 (tested)
|
|
- AT91SAM9N12 (not tested, Should work)
|
|
|
|
As soon as your nand flash software ECC works, you can enable PMECC.
|
|
|
|
To use PMECC in this driver, the user needs to set:
|
|
1. the PMECC correction error bits capability: CONFIG_PMECC_CAP.
|
|
It can be 2, 4, 8, 12 or 24.
|
|
2. The PMECC sector size: CONFIG_PMECC_SECTOR_SIZE.
|
|
It only can be 512 or 1024.
|
|
|
|
Take AT91SAM9X5EK as an example, the board definition file likes:
|
|
|
|
/* PMECC & PMERRLOC */
|
|
#define CONFIG_ATMEL_NAND_HWECC 1
|
|
#define CONFIG_ATMEL_NAND_HW_PMECC 1
|
|
#define CONFIG_PMECC_CAP 2
|
|
#define CONFIG_PMECC_SECTOR_SIZE 512
|