RSDEC-DBLK-XM-U3 Lattice, RSDEC-DBLK-XM-U3 Datasheet - Page 17

• Manufacturer Part Number: RSDEC-DBLK-XM-U3
• Description: Encoders, Decoders, Multiplexers & Demultiplexers Dynamic Block Reed Solomon Decoder
• Manufacturer: Lattice

Specifications of RSDEC-DBLK-XM-U3

• Factory Pack Quantity: 1

Lattice Semiconductor
IPUG52_01.6, December 2010
Timing Specifications
The decoder receives the data in blocks. The assertion of signal ibstart indicates the first symbol of the new
block of data at the input of the decoder. The ibstart signal should be asserted only during the first clock cycle of
a data block. The ibstart signal should not be re-asserted until the decoder is ready to receive the next block of
data as indicated by rfib going high. The signal rfib can be used to generate the ibstart signal. If a new block
of input data has to be applied before the decoder is ready for a new block, the decoder operation should be reset
using the synchronous reset signal sr.
Figure 2-3
The output rfi goes high after reset to indicate the core is ready to receive input data. After ibstart signal is
asserted, the decoder reads in the data block sequentially and starts the decoding process. When the decoded
data is given at the output, obstart is asserted for one clock cycle during the first decoded output symbol. The
output obend is asserted for one clock cycle when the last decoded symbol is given at the dout port.
Figure 2-3. RS Decoder Normal Operation Timing Diagram
Figure 2-4
reinitializes the decoder state similar to power on reset state. The output data stops appearing at the output. The
decoder operation can be started again by asserting the ibstart signal.
ibstart
blocksize
numchks
puncsel
dout
ddel
outvalid
obstart
obend
errfnd
errcnt
erscnt
rstn
rfib
ers
din
clk
fail
ce
sr
rfi
shows the I/O signals’ status after asynchronous reset rstn is asserted at the beginning of the block.
illustrates the output status when sr is asserted. When sr is asserted during the decoding process, it
AI0
c1
p
n
1
AI1
AI2
AIn-3
AIn-2
AIn-1
BI0
p
c2
o
2
BI1
BI2
17 Dynamic Block Reed-Solomon Decoder User’s Guide
0
0
BIo-3
BIo-2
BIo-1
AO0
CI0
AI0
c3
p3
p
AO1 AO2
CI1
AI1
Functional Description
AI2
CI2
CIp-3
AOn-3 AOn-2 AOn-1
AIn-3 AIn-2 AIn-1
CIp-2
CIp-1
4
2