Medium throughput, compact Reed Solomon decoder

This implementation of a M=8 Reed Solomon decoder has been designed to use a minimum set of resources whilst maintaining a medium throughput and flexible configuration. It supports per-packet setting for codeword length, message length, generator polynomial start index and fully supports the maximum number of erasures. It requires 16k gates and one 8x256 bit single port synchronous SRAM. The clock frequency needs to be 3x the message bit rate. The core benefits from an APB interface for setup and control, plus an AXI4-Stream master slave interface for the data plane. The AXI4-Stream interface fully supports bursty input data and backpressure on the output.