Hardware/software co-design of a fuzzy RISC processor

In this paper, we show how hardware/software co-evaluation can be applied to instruction set definition. As a case study, we show the definition and evaluation of instruction set extensions for fuzzy processing. These instructions are based on the use of subword parallelism to fully exploit the processor´s resources by processing multiple data streams in parallel. The proposed instructions are evaluated in software and hardware to gain a balanced view of the costs and benefits of each instruction. We have found that a simple instruction optimized to perform fuzzy rule evaluation offers the most benefit to improve fuzzy processing performance. The instruction set extensions are added to a RISC processor core based on the MIPS instruction set architecture. The core has been described in VHDL so that hardware implementations can be generated using logic synthesis