Samsung S5PC110, Manual

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S5PC110_UM 4 NAND FLASH CONTROLLER
4-8
4.3.7 4-BIT ECC PROGRAMMING GUIDE (ENCODING)
1. To use 4-bit ECC in software mode, set the MsgLength to 0(512-byte message length) and the ECCType to
“10”(enable 4bit ECC). ECC module generates ECC parity code for 512-byte write data. To reset ECC value
write the InitMECC (NFCONT[5]) bit as ‘1’ and clear the MainECCLock (NFCONT[7]) bit to ‘0’(Unlock) before
writing data.
MainECCLock (NFCONT[7]) bit controls whether ECC Parity code is generated or not.
2. The 4-bit ECC module generates ECC parity code internally whenever data is written.
3. After you finish writing 512-byte data (not including spare area data), the parity codes are automatically
updated to NFMECC0 and NFMECC1 registers. If you use 512-byte NAND Flash memory, you can program
these values to spare area. However, if you use NAND Flash memory more than 512-byte page, you cannot
program immediately. In this case, you have to copy these parity codes to other memory like DRAM. After
writing all main data, you can write the copied ECC values to spare area.
The parity codes have self-correctable information including parity code itself.
4. To generate spare area ECC parity code, set the MsgLength to 1(24-byte message length) and the ECCType
to “10”(enable 4bit ECC). ECC module generates ECC parity code for 24-byte write data. To reset ECC value
write the InitMECC (NFCONT[5]) bit as ‘1’ and clear the MainECCLock (NFCONT[7]) bit to ‘0’(Unlock) before
writing data.
MainECCLock (NFCONT[7]) bit controls whether ECC Parity code is generated or not.
5. Whenever data is written, the 4-bit ECC module generates ECC parity code internally.
6. When you finish writing 24-byte meta or extra data, the parity codes are automatically updated to NFMECC0
and NFMECC1 registers. You can program these parity codes to spare area.
The parity codes have self-correctable information including parity code itself.