Forward Error Correction (FEC) codes such as Low Density Parity Check (LDPC) codes provide a means to control errors in data transmissions over unreliable or noisy communication channels. The LDPC Encoder/Decoder core provides an optimized block for encoding and soft-decision decoding of these codes. Custom and standardized LDPC codes are supported through the ability to specify the parity check matrix either through configuration of code memory or alternatively over an AXI4-Lite bus.