The high latency of memory operations is a problem in both sequential and parallel computing. Multithreading is a technique, which can be used to eliminate the delays caused by the high latency. This happens by letting a processor to execute other processes (threads) while one process is waiting for the completion of a memory operation. In this paper we investigate the implementation of multithreading in the processor-level. As a result we outline and evaluate a MultiThreaded VLIW processor Architecture with functional unit Chaining (MTAC), which is specially designed for PRAM-style parallelism. According to our experiments MTAC offers remarkably better performance than a basic pipelined RISC architecture and chaining improves the exploitation of instruction level parallelism to a level where the achieved speedup corresponds to the number of functional units in a processor.

PRAM, VLIW, multithreading, chaining