Power-efficient Instruction Encoding Optimization for Various Architecture Classes

A huge application domain, in particular, wireless and handheld devices strongly requires flexible and power-efficient hardware with high performance. This can only be achieved with Application Specific Instruction-Set Processors (ASIPs). A key problem is to determine the instruction encoding of the processors for achieving minimum power consumption in the instruction bus and in the instruction memory. In this paper, a framework for determining power-efficient instruction encoding in RISC and VLIW architectures is presented. We have integrated existing and novel techniques in this framework and propose novel heuristic approaches. The framework accepts an existing processor’s instruction-set and a set of implementations of various applications. The output, which is an optimized instruction encoding under the constraint of a well-defined cost model, minimizes the power consumption of the instruction bus and the instruction memory. This results in strong reduction of the overall power consumption. Case studies with commercial embedded processors show the effectiveness of this framework.