VS1005g Datasheet
10 VS1005 PERIPHERALS AND REGISTERS
As the check symbols are 10 bits they must be organized into memory in this format before
check symbol decoding is started. The encoder expects them to be in LSB bits (9:0) in con-
secutive memory locations. The decoder returns the number of total errors and the number
of errors in data symbols. Only the data symbol errors are returned as location / magnitude
pairs when Reed Solomon decoder has finished the calculation. These errors must be fixed
by software to the code word by XORing magnitude to the error location data. The location /
magnitude pairs are stored in memory.
Reed Solomon codecs use a shared interrupt source INT_XPERIP. The source of interrupt is
stored in register DSPI_ST where the decoder has one bit for Reed Solomon encoder and two
bits for Reed Solomon decoder. To enable the interrupts the DSPI_ST_IENA must be set.
Reed Solomon interrupts in DSPI_STATUS Register
Name
Bits Description
DSPI_ST_IENA
14 Interrupt enable, active high
DSPI_ST_BMCSF
DSPI_ST_RSDEC
DSPI_ST_RSENC
8
7
6
Reed-Solomon decode error correction ready
Reed-Solomon decode ready
Reed-Solomon encode ready
Reed-Solomon Registers
Reg Type Reset Abbrev
Description
0xFC70
0xFC71
0xFC72
0xFC73
0xFC74
0xFC75
0xFC76
r
0
0
0
0
0
0
0
RS_ST
RS_CF
Reed-Solomon status for encoder and decoder
Reed-Solomon control and configuration register
r/w
r/w
r/w
r/w
r/w
r
RS_EPNTR Reed-Solomon encoder memory pointer
RS_ELEN Reed-Solomon encoder data length
RS_DPNTR Reed-Solomon decoder memory pointer
RS_DLEN
RS_DATA
Reed-Solomon decoder data length
Data read port
RS_ST Bits
Name
Bits Description
RS_ST_DERR
12:8 Number of errors in decoded code word
RS_ST_DFFAIL
RS_ST_DFRDY2
RS_ST_DFBUSY
6
5
4
Decoder fix algorithm found too many errors
Decoder fix algorithm completed
Decoder fix algorithm is calculating magni-
tude and location pairs
RS_ST_DFRDY1
RS_ST_DFAIL
RS_ST_DERR
RS_ST_DOK
3
2
1
0
Decoder fix algorithm part 1 completed
Code word errors can not be fixed
Code word has errors
Code word does not contain errors
RS_ST_DERR is the error count register. When R-S decoder fix algorithm has completed the
number of location/magnitude pairs is stored to this register.
RS_ST_DFFAIL register is set when the decoder algorithm could not fix all the errors in code
word.
RS_ST_DFRDY2, RS_ST_DFBUSY and RS_ST_DFRDY1 are monitoring the status of R-S
Version: 0.2, 2012-03-16
58
ETC [ ETC ]
