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1 What is a VLIW Processor?

Recent high performance processors have depended on Instruction Level Parallelism (ILP) to achieve high execution speed. ILP processors achieve their high performance by causing multiple operations to execute in parallel, using a combination of compiler and hardware techniques. Very Long Instruction Word (VLIW) is one particular style of processor design that tries to achieve high levels of instruction level parallelism by executing long instruction words composed of multiple operations. The long instruction word called a MultiOp consists of multiple arithmetic, logic and control operations each of which would probably be an individual operation on a simple RISC processor. The VLIW processor concurrently executes the set of operations within a MultiOp thereby achieving instruction level parallelism. The remainder of this article discusses the technology, history, uses and the future of such processors.

Binu K. Mathew