The NSR processor

The NSR processor is a general-purpose computer structured as a collection of self-timed blocks. These blocks operate concurrently and cooperate by communicating with other blocks using self-timed communication protocols. The blocks that make up the NSR processor correspond to standard synchronous pipeline stages such as instruction fetch, instruction decode, execute, memory interface and register file, but each operates concurrently as a separate self-timed process. In addition to being internally self-timed, the units are decoupled through self-timed first-in first-out (FIFO) queues between each of the units which allows a high degree of overlap in instruction execution. Branches, jumps, and memory accesses are also decoupled through the use of additional FIFO queues which can hide the execution latency of these instructions. A prototype implementation of the NSR processor has been constructed using Actel FPGAs (field programmable gate arrays).