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| author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 |
|---|---|---|
| committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 |
| commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
| tree | 65ca85f13617aee1dce474596800950f266a456c /roms/u-boot/doc/README.atmel_pmecc | |
| download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip | |
Diffstat (limited to 'roms/u-boot/doc/README.atmel_pmecc')
| -rw-r--r-- | roms/u-boot/doc/README.atmel_pmecc | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/roms/u-boot/doc/README.atmel_pmecc b/roms/u-boot/doc/README.atmel_pmecc new file mode 100644 index 00000000..cf8373b5 --- /dev/null +++ b/roms/u-boot/doc/README.atmel_pmecc @@ -0,0 +1,29 @@ +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 |