VSC6134
Datasheet
Interleaving Buffer
The interleaving buffer performs the 16× byte-interleaving of the 255-symbol Reed Solomon encoded
codewords to produce FEC frames. This is according to ITU-T G.709 recommendation. Interleaved data
is passed to the BCH encoder.
The interleaving buffer I/O descriptions are shown in the following table.
Table 37. Interleaving Buffer I/O Description
Name
Direction
IN
Function
reset_n
Active low reset.
tx_clk
IN
Transmit clock.
bch_en
IN
Unused and tied high.
mpu_fec_disable
wrvalid
IN
FEC disable overwrites the parity bytes with zeros.
Write valid indicates when the data from the encoder is valid.
Encoder frame start marks each 255 byte start.
Encoder data in.
IN
fstart
IN
encdatain[63:0]
nfa
IN
IN
New frame alignment.
intlvedout[63:0]
mpu_rdptr[8:0]
mpu_wrptr[8:0]
startsubframe
init_done
OUT
OUT
OUT
OUT
OUT
Data out in OTUk format.
Read pointer out.
Write pointer out.
OTUk frame start is aligned with the first word of the frame.
Initialization done.
2.7.7.2
Enhanced FEC Encoder
For a description of the enhanced FEC encoder, see “EFEC,” page 40.
Table 38. EFEC Encoder I/O Description
Name
Direction
IN
Function
clk
Transmit clock
Transmit reset
New frame alignment
Data in
reset_n
IN
n_fa
IN
data_in[63:0]
data_in_we
data_out[63:0]
fstart_out
read_ptr[5:0]
write_ptr
init_done
IN
IN
Data in write enable
Data out
OUT
OUT
OUT
OUT
OUT
Frame start out
Read pointer
Write pointer
Initialization done
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VMDS-10185 Revision 4.0
July 2006
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
