4-/ 8-/ 12-/ 16-Bit Ecc - Samsung S5PC110 Manual

S5PC110_UM

4.3.2 1-/ 4-/ 8-/ 12-/ 16-BIT ECC

NAND flash controller supports 1-/ 4-/ 8-/ 12-/ 16-bit ECC.
For 1-bit ECC, NAND flash controller comprises ECC modules for main and spare (meta) data. Main data ECC
module generates ECC parity code for 2048 bytes (maximum) data/ message length, whereas spare (meta) data
ECC module generates ECC Parity code for 32 bytes (maximum).
For 4-bit ECC, NAND flash controller comprises of an ECC module. It generates 512 or 24 bytes of ECC parity
code. Set MsgLength (NFCONF[25]) to select 512 or 24 bytes message length.
For 8-/ 12-/ 16-bit ECC, NAND flash controller comprises ECC modules for each ECC. You can select data/
message length for main and spare (meta) data length. Usually, the length of main data is 512 bytes, and the
length of spare (meta) data depends on user application.
Since these ECC modules support variable length of main and spare (meta) data, you must set the ECC parity
conversion codes to handle free page (For more information on ECC parity conversion codes, refer to the
Free page specifies an erased page. The value of erased page is '0xff'. Therefore, set the ECC parity conversion
codes to generate '0xff' ECC parity codes for all '0xff' data. This allows ECC module to detect errors on a free
page.
ECC parity codes are described as follows:
•
28-bit ECC Parity Code = 22-bit Line parity + 6-bit Column Parity
•
10-bit ECC Parity Code = 4-bit Line parity + 6bit Column Parity
Each 1-/ 4-/ 8-/ 12-/ 16-bit ECC module guarantees up to 1-/ 4-/ 8-/ 12-/ 16-bit errors, respectively. If the errors
cross the number of guaranteed errors, the result cannot be guaranteed.
and show 1-bit ECC parity code assignment.
4.3.4
4.3.3
4 NAND FLASH CONTROLLER
4.3.11
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