Preliminary
www.ti.com
Architecture
Table 5-19. Misaligned Nibble Mapping of Message in 16-bit NAND (1 Unused Nibble)
16-Bit Word
Byte Offset
4-Bit Most Significant Nibble
4-Bit Less Significant Nibble
0
Nibble S-3
Nibble S-4
(MSB) Nibble S-1
Nibble S-2
2
Nibble S-7
Nibble S-8
Nibble S-5
Nibble S-6
⋮
⋮
⋮
⋮
⋮
(S+1)/2 - 4
Nibble 4
Nibble 3
Nibble 6
Nibble 5
(S+1)/2 - 2
Nibble 0 (LSB)
Nibble 2
Nibble 1
Table 5-20. Misaligned Nibble Mapping of Message in 16-bit NAND (2 Unused Nibble)
16-Bit Word
Byte Offset
4-Bit Most Significant Nibble
4-Bit Less Significant Nibble
0
Nibble S-3
Nibble S-4
(MSB) Nibble S-1
Nibble S-2
2
Nibble S-7
Nibble S-8
Nibble S-5
Nibble S-6
⋮
⋮
⋮
⋮
⋮
(S+2)/2 - 4
Nibble 3
Nibble 2
Nibble 5
Nibble 4
(S+2)/2 - 2
Nibble 1
Nibble 0 (LSB)
Table 5-21. Misaligned Nibble Mapping of Message in 16-bit NAND (3 Unused Nibble)
16-Bit Word
Byte Offset
4-Bit Most Significant Nibble
4-Bit Less Significant Nibble
0
Nibble S-3
Nibble S-4
(MSB) Nibble S-1
Nibble S-2
2
Nibble S-7
Nibble S-8
Nibble S-5
Nibble S-6
⋮
⋮
⋮
⋮
⋮
(S+3)/2 - 4
Nibble 2
Nibble 1
Nibble 4
Nibble 3
(S+3)/2 - 2
Nibble 0 (LSB)
Note that many other cases exist than the ones represented above, for example, where the message
does not start on a word boundary.
5.2.4.12.3.2.4 Memory Mapping of the ECC
The ECC (or remainder) is presented by the BCH module as a single 104-bit (or 52-bit), little-endian
vector. It is up to the software to fetch those 13 bytes (or 6 bytes) from the modules interface, then
store them to the NANDs spare area (page write) or to an intermediate buffer for comparison with the
stored ECC (page read). There are no constraints on the ECC mapping inside the spare area: it is a
softwarecontrolled operation.
However, it is advised to maintain a coherence in the respective formats of the message or the ECC
remainder once they have been read out of the NAND. The error correction algorithm works from the
complete codeword (concatenated message and remainder) once an error as been detected. The
creation of this codeword should be made as straightforward as possible.
617
SPRUGX9 – 15 April 2011
General-Purpose Memory Controller (GPMC)
© 2011, Texas Instruments Incorporated
Содержание TMS320C6A816 Series
Страница 2: ...Preliminary 2 SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 92: ...92 Read This First SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1122: ...1122 Multichannel Audio Serial Port McASP SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1562: ...1562 Real Time Clock RTC SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1658: ...1658 Timers SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1750: ...1750 UART IrDA CIR Module SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...
Страница 1984: ...1984 Universal Serial Bus USB SPRUGX9 15 April 2011 Submit Documentation Feedback 2011 Texas Instruments Incorporated...