Concatenated Viterbi decoder / Reed-Solomon decoder

The SALxx400D product is a concatenated Viterbi decoder / de-interleaver / Reed-Solomon decoder of the de-facto industry standard (7, 1/2) / (255, 239) concatenated code.

The basic Viterbi code is a constraint length 7, rate 1/2 transparent code which is well suited to channels with predominantly Gaussian noise. In addition to the nominal rate 1/2 code, the device supports punctured rates 2/3, 3/4, 5/6, and 7/8. The convolutional code is of the non-systematic, non-recursive type, with connection polynomials g1 = 171, and g2 = 133.

The de-interleaver is a simple byte interleaver with a programmable depth, in which bytes are written as columns and read out as Reed-Solomon codewords.

The Reed-Solomon decoder uses the field GF(256), whose primitive polynomial is p(x) = x⁸ + x⁴ + x³ + x² + 1. It is capable of very high speed operation. Its coefficients are taken from the generator polynomial g(x) = (x-1)(x-α^j)(x-α²)...(x-α^2T-1).

Benefits

Viterbi Decoder
o Constraint length 7
o Nominal code rate 1/2
o Punctured rates 2/3, 3/4, 5/6, 7/8

Byte interleaver with programmable depth and length

Reed-Solomon decoder
o n = 255, k = 239, t = 8
o 8-bit symbols
o Field generator polynomial:
F(x) = x⁸ + x⁴ + x³ + x² + 1
o Generator polynomial:
g(x) = (x-1)(x-α^j)(x-α²)...(x-α^2T-1)

Simple handshake protocol for reliable interfacing

Fully synchronous design

High speed operation 200 Mbps operation

Low latency

Documentation

Datasheet

Ordering Information

SALxx400D-v

HDL license -- Verilog source code

$contact us

SALxx400D-x

Netlist license -- Xilinx netlist

$contact us

Contact us at sales@salamander-ecc.com for more information, or to request a custom designed solution.

Reed-Solomon, Viterbi, and Turbo Codes. Salamander Error Correction specializes in the design and marketing of Verilog IP modules for Forward Error Correction.

Salamander Error Correction

5330 Carroll Canyon Rd

San Diego, CA 92121

(858) 373-2112

Fax: (858) 373-1224

sales@salamander-ecc.com