stlc1510 STMicroelectronics, stlc1510 Datasheet - Page 14

• Manufacturer Part Number: stlc1510
• Description: Northenlite G.lite Dmt Transceiver
• Manufacturer: STMicroelectronics

STLC1510
The Utopia Rx FIFO has the following additional at-
tributes:
5.3 Reed Solomon Forward Error Correction
Forward error correction is provided with byte-wise
Reed Solomon (RS) Encoding and Decoding in a 256
element Galois Field.
5.3.1 Parameters
The following parameter values for
supported:
Furthermore
The Reed-Solomon Code Word length is
its value results from the selection of
the number of data bytes
by
length is
14/40
B
Software programmable generation of the flag
TX_CLAV (CeLl AVailable, TX direction) via
registers. This translates to the FIFO having a
software programmable depth.
Software programmable generation of the flag
TX_BP (Back Pressure, TX direction) via
registers. This allows the FIFO to throttle
incoming data flow, while still accepting data
that was already en route when the flag was
asserted.
Software programmable generation of the flag
RX_CLAV (CeLl AVailable, RX direction) via
registers. This translates to the FIFO having a
software programmable depth.
the combination
allowed, while not required.
byte wise coding over
and hence
=
S
R
R S
(RS-FEC)
1
B
=
=
=
1 2 4 8 16
0 4 8 16
16
2
is integer,
N
60
48
F EC
for upstream. The RS Data Word
144
S
255
1
B
G F 256
.
for
per Data Frame, where-
and
downstream,
D
,
S
=
S
1
and
N
and
F EC
is
R
R
, and
, and
are
or
and the RS Code Word length is
The code word is transmitted over
and hence the number of bytes per Data Frame is
The Galois Field primitive element
the zero of the primitive polynomial
The Reed-Solomon generator polynomial is
The RS encoder does not introduce latency. RS de-
coding has a latency of at least
per bound of the latency is given by the actual
decoder implementation.
The transmitter and receiver provide synchronization
of the RS Code Words.
5.4 Bit Mapper/Demapper Module (MAP)
5.4.1 Features
G.992.2 Compliant constellation encoder, up to
15 bits per sub-carrier capability.
Support for 1-bit per sub-carrier modulation
(BAM) and idle sub-carriers.
Constellation encoder, Q1.15 complex fixed
point output.
Bit unpacking and packing from/to 256-byte
data frame.
Support for pilot tone insertion.
Support for REVERB, SEGUE and MEDLEY
generation.
Support for random 4-QAM generation.
No trellis coding.
Implemented as a peripheral device.
N
K
G x
F EC
B’
F EC
p x
=
=
=
=
N
-------------- -
=
K
F EC
S
R 1
k
S
x
+
=
–
8
0
R
+
B
=
x
x
+
4
+
B
1
+
+
x
k
1
3
+
+
R
--- -
S
x
2
N
+
S
1
, whereby the up-
DMT symbols,
is defined by