Variable-length, high-speed asynchronous decoder circuit

Abstract

There is disclosed a decoder circuit () for decoding input data coded using a variable length coding technique, such as Huffman coding. The decoder circuit () comprises an input buffer (), a logic circuit () coupled to the input buffer (), and an output buffer () coupled to the logic circuit (). The logic circuit () includes a plurality of computational logic stages for decoding the input data, the plurality of computational logic stages arranged in one or more computational threads. At least one of the computational threads is arranged as a self-timed ring, wherein each computational logic stage in the ring produces a completion signal indicating either completion or non-completion of the computational logic of the associated computational logic stage. Each completion signal is coupled to a previous computational logic stage in the ring. The previous computational logic stage performs control operations when the completion signal indicates completion and performs evaluation of its inputs when the completion signal indicates non-completion.