参数资料
型号: IPR-RSDEC
厂商: Altera
文件页数: 22/38页
文件大小: 0K
描述: IP REED-SOLOMON DECODER RENEW
标准包装: 1
系列: *
类型: MegaCore
功能: Reed-Solomon 解码器
许可证: 续用许可证
3–2
Chapter 3: Functional Description
Background
For example, for the following information:
3
g(x) = ?? ( x – ? i + i0 )
i = 0
a is a root of the binary primitive polynomial x 8 + x 7 + x 2 + x + 1
i0 = 120
You can calculate the following parameters:
R –1=3
a = 1 ( ? is to the power 1 times i )
The field polynomial can be obtained by replacing x with 2, thus:
2 8 + 2 7 + 2 2 +2 + 1 = 391
Erasures
In normal operation, the RS decoder detects and corrects symbol errors.
The number of symbol errors that can be corrected, C , depends on the number of
check symbols, R and is given by C ? R /2.
If the location of the symbol errors is marked as an erasure, the RS decoder can correct
twice as many errors, so C ? R .
1
Erasures are symbol errors with a known location.
External circuitry identifies which symbols have errors and passes this information to
the decoder using the eras_sym signal. The eras_sym input indicates an erasure (when
the erasures-supporting decoder option is selected).
The RS decoder can work with a mixture of erasures and errors.
A codeword is correctly decoded if (2 e + E ) ? R
where:
e = errors with unknown locations
E = erasures
R = number of check symbols.
For example, with ten check symbols the decoder can correct ten erasures, or five
symbol errors, or four erasures and three symbol errors.
If the number of erasures marked approaches the number of check symbols, the
ability to detect errors without correction ( decfail asserted) diminishes. Refer to
Table 3–1 on page 3–4 .
Shortened Codewords
A shortened codeword contains fewer symbols than the maximum value of N , which
is 2 m –1. A shortened codeword is mathematically equivalent to a maximum-length
code with the extra data symbols at the start of the codeword set to 0.
For example, (204,188) is a shortened codeword of (255,239). Both of these codewords
use the same number of check symbols, 16.
Reed-Solomon Compiler
User Guide
November 2013 Altera Corporation
相关PDF资料
PDF描述
EMM10DRSI CONN EDGECARD 20POS DIP .156 SLD
UCL1C221MCL6GS CAP ALUM 220UF 16V 20% SMD
135104-01-36.00 CBL SMA R/A PLUG-PLUG RG316 36"
UCL1C680MCL1GS CAP ALUM 68UF 16V 20% SMD
336306-12-0300 CABL AMC-SMA RP BLKHD JACK 300MM
相关代理商/技术参数
参数描述
IPR-RSENC 功能描述:开发软件 Reed-Solomon Encoder MegaCore RENEWAL RoHS:否 制造商:Atollic Inc. 产品:Compilers/Debuggers 用于:ARM7, ARM9, Cortex-A, Cortex-M, Cortex-R Processors
IP-RSCODECII 功能描述:开发软件 Reed-Solomon Enc Dec MegaCore RoHS:否 制造商:Atollic Inc. 产品:Compilers/Debuggers 用于:ARM7, ARM9, Cortex-A, Cortex-M, Cortex-R Processors
IP-RSDEC 功能描述:开发软件 Reed-Solomon Decoder MegaCore RoHS:否 制造商:Atollic Inc. 产品:Compilers/Debuggers 用于:ARM7, ARM9, Cortex-A, Cortex-M, Cortex-R Processors
IPR-SDI 功能描述:开发软件 Video Interface SDI MegaCore RENEWAL RoHS:否 制造商:Atollic Inc. 产品:Compilers/Debuggers 用于:ARM7, ARM9, Cortex-A, Cortex-M, Cortex-R Processors
IPR-SDI-II 功能描述:开发软件 SDI II Video MegaCore RENEWAL RoHS:否 制造商:Atollic Inc. 产品:Compilers/Debuggers 用于:ARM7, ARM9, Cortex-A, Cortex-M, Cortex-R Processors