1. A decoder for decoding Reed-Solomon encoded data comprising input means for receiving said encoded data in a stream of code blocks, memory means coupled to said input means for storing said received encoded data, processing means coupled to said memory means for performing decoding functions on said stored encoded data and returning processed data to said memory, output means coupled to said memory means for transmitting decoded data from said decoder, said memory means including three identical memories, one for storing encoded data to be decoded, one for storing data being decoded, and one for storing decoded data being transmitted out of the decoder, each memory having its own addressing means and data output terminals, means for determining when each of said input means, processing means and output means have completed their respective functions on a different code block, and switching means responsive to said determining means for sequentially swapping memories between said input means, processing means and output means, whereby overall pipelining of code blocks is provided through said decoder without physically transferring code blocks through more than one memory.