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Decodes a code word so that it contains the entire data word sequence unchanged, preceded by the parity words. Performs decoding on a Bose-Chaudhari-Hocquenghem (BCH) encoded bit stream using the Berlekamp algorithm for binary BCH codes.


input bit stream

Bit sequence representing the code word to decode.



Values of the code word length (n), data word length (k), and error correcting capacity (t), in bits. The n, k, and t values for BCH encoding are interrelated such that specifying two values constrains the third value. Select from a set of well-known (n,k,t) triples that are widely used for BCH encoding or specify an arbitrary triple by entering three comma-separated integers. The encoding scheme takes in a bit data word of k bits and produces a code word of n bits.

Code Word Length Limits

Default: 7, 4, 1


error in

Error conditions that occur before this node runs. The node responds to this input according to standard error behavior.

Default: no error



A Boolean that determines whether the internal state of the decoder is cleared.

TRUE Clears any buffered bits from previous iterations. Also initializes the Galois field structure corresponding to the BCH n, k, t values.
FALSE Continues decoding from the previous iteration. Any buffered bits from the previous iteration are added to the beginning of the input bit stream prior to decoding.

The initialization of the Galois field structure may consume significant amounts of time for code word lengths greater than 127. Once initialized, the same Galois field structure is used in every iteration thereafter, provided reset? is FALSE. To improve the performance of this node, set reset? to TRUE for the first iteration and FALSE thereafter.

Default: TRUE


output bit stream

Bit sequence decoded by this node.


error out

Error information. The node produces this output according to standard error behavior.