TMP92CF30
2009-06-12
92CF30-223
NAND Flash ECC Register 4
7 6 5 4 3 2 1 0
bit Symbol
ECCD7 ECCD6
ECCD5
ECCD4
ECCD3
ECCD2 ECCD1 ECCD0
Read/Write
R
Reset State
0 0 0 0 0 0 0 0
Function
NAND Flash ECC Register (7-0)
NDECCRD4
(08CCH)
15 14 13 12 11 10 9 8
bit Symbol
ECCD15 ECCD14
ECCD13
ECCD12
ECCD11
ECCD10 ECCD9 ECCD8
Read/Write
R
Reset State
0 0 0 0 0 0 0 0
(08CDH)
Function
NAND Flash ECC Register (15-8)
Figure3.11.7 NAND Flash ECC Registers
The NAND Flash ECC register is used to read ECC generated by the ECC generator.
After valid data has been written to or read from the NAND Flash, setting
NDFMCR0<ECCE> to “0” causes the corresponding ECC to be set in this register. (The
ECC in this register is updated when NDFMCR0<ECCE> changes from “1” to “0”.)
When Hamming codes are used, 22 bits of ECC are generated for up to 256 bytes of valid
data. In the case of Reed-Solomon codes, 80 bits of ECC are generated for up to 518 bytes of
valid data. A total of 80 bits of registers are provided, arranged as five 16-bit registers.
These registers must be read in 16-bit units and cannot be accessed in 32-bit units.
After ECC calculation has completed, in the case of Hamming codes, the 16-bit line
parity for the first 256 bytes is stored in the NDECCRD0 register, the 6-bit column parity
for the first 256 bytes in the NDECCRD1 register (<ECCE7:2>), the 16-bit line parity for
the second 256 bytes in the NDECCRD2 register, and the 6-bit column parity for the second
256 bytes in the NDECCRD3 register (<ECCD7:2>). In this case, the NDECCRD4 register
is not used.
In the case of Reed-Solomon codes, 80 bits of ECC are stored in the NDECCRD0,
NDECCRD1, NDECCRD2, NDECCRD3 and NDECCRD4 registers.
Note: Before reading ECC from the NAND Flash ECC register, be sure to set NDFMCR0<ECCE> to “0”. The ECC in
the NAND Flash ECC register is updated when NDFMCR0<ECCE> changes from “1” to “0”. Also note that
when the ECC in the ECC generator is reset by NDFMCR0<ECCRST>, the contents of this register are not
reset.
Register
Name
Hamming Reed-Solomon
NDECCRD0
[15:0] Line parity
(for the first 256 bytes)
[15:0]
Reed-Solomon ECC code 79:64
NDECCRD1
[7:2] Column parity
(for the first 256 bytes)
[15:0]
Reed-Solomon ECC code 63:48
NDECCRD2
[15:0] Line parity
(for the second 256 bytes)
[15:0]
Reed-Solomon ECC code 47:32
NDECCRD3
[7:2] Column parity
(for the second 256 bytes)
[15:0]
Reed-Solomon ECC code 31:16
NDECCRD4
Not in use
[15:0]
Reed-Solomon ECC code 15:0
Summary of Contents for TLCS-900/H1 Series
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