VS1005g Datasheet
10 VS1005 PERIPHERALS AND REGISTERS
ing symbols from peripheral memory from address RS_DPNTR onwards. The symbols are
fetched from memory as 8-bit or 10-bit symbols but are always forwarded to decoder as 10-bit
symbols where bits [9:8] are zero if RS_CF_D10B is reset. The decoder decodes RS_DLEN
number of symbols and then reset RS_CF_DENA. Also an DSPI_ST_RSDEC interrupt request
is generated.
RS_CF_DMODE register should be set when decoding nand flash data (10-bit NF). When reset
the 8-bit code is used (RF).
RS_CF_SEL is used to select encoded parity symbols. The selected parity symbol can be read
from RS_DATA register.
RS_CF_ENF selects between two data input modes. When set the encoder uses nand flash
output data register as input. When reset the data is fetched from peripheral memory.
RS_CF_ESTR initializes the R-S encoder i.e. starts a new encoding sequence. This register
is reset automatically when first symbol is encoded. The encoder does not need encode-end
register as the check symbols are updated on-the-fly and are readable from the RS_DATA port
after the current operation has finished.
RS_CF_EENA enables the R-S encoder. When RS_CF_ENF is set the encoder is encoding
symbols as they are written to nand flash. If RS_CF_ENF is reset the encoder starts reading
symbols from peripheral memory from address RS_EPNTR onwards. The symbols are fetched
from memory as 8-bit data but are forwarded to encoder as 10-bit symbols where bits [9:8]
are always zero. The big endian byte order is expected. The encoder encodes RS_ELEN
number of symbols and then reset RS_CF_EENA. Also an DSPI_ST_RSENC interrupt request
is generated.
RS_CF_EMODE register should be set when encoding nand flash data (10-bit). When reset
the 8-bit code is used (RF).
RS_EPNTR and RS_DPNTR are the 11-bit address registers for Reed-Solomon encoder and
decoder. The start address of data is written to these registers prior the encode or decode is
enabled. The big endian byte order is expected.
RS_ELEN and RS_DLEN are the code length registers for the encoder and decoder. The
length is given as the number of 8-bit symbols. For decoder the symbols can also be 10-bit
parity check symbols.
RS_DATA is a data read port for several data registers.
RS_OPORT Mux Control Bits
DSPI_CF[15:12] register
Mux input
1111-1100
1011
1010-0100
0011
Reserved
R-S decoder total errors (data + check symbols), 5 bits
Reserved
R-S decoder CSF index, 10 bits
R-S decoder BM index, 9 bits
0010
0001
R-S decoder syndrome index, 10 bits
0000 R-S encoder parity word as selected with RS_CF[7:4], 16 bits
Version: 0.2, 2012-03-16
60
ETC [ ETC ]
