Other factor which governs the selection of ecc-scheme is oob-size.
Higher ECC schemes require more OOB/Spare area to store ECC syndrome,
so the device should have enough free bytes available its OOB/Spare
- area to accomodate ECC for entire page. In general following expression
- helps in determining if given device can accomodate ECC syndrome:
+ area to accommodate ECC for entire page. In general following expression
+ helps in determining if given device can accommodate ECC syndrome:
"2 + (PAGESIZE / 512) * ECC_BYTES" >= OOBSIZE"
where
OOBSIZE number of bytes in OOB/spare area
Example(b): For a device with PAGESIZE = 2048 and OOBSIZE = 128 and
trying to use BCH16 (ECC_BYTES=26) ecc-scheme.
Number of ECC bytes per page = (2 + (2048 / 512) * 26) = 106 B
- which can be accomodate in the OOB/Spare area of this device
+ which can be accommodated in the OOB/Spare area of this device
(OOBSIZE=128). So this device can use BCH16 ecc-scheme.