The demand for energy-efficient and high performance embedded systems drives the evolution of new hardware architectures, including concepts like approximate computing. This paper presents a novel reconfigurable embedded platform named "phoeniX", using the standard RISC-V ISA, maximizing energy efficiency while maintaining acceptable application-level accuracy. The platform enables the integration of approximate circuits at the core level with diverse structures, accuracies, and timings without requiring modifications to the core, particularly in the control logic. The platform introduces novel control features, allowing configurable trade-offs between accuracy and energy consumption based on specific application requirements. To evaluate the effectiveness of the platform, experiments were conducted on a set of applications, such as image processing and Dhrystone benchmark. The core with its original execution engine, occupies 0.024mm2 of area, with average power consumption of 4.23mW at 1.1V operating voltage, average energy-efficiency of 7.85pJ per operation at 620MHz frequency in 45nm CMOS technology. The configurable platform with a highly optimized 3-stage pipelined RV32I(E)M architecture, possesses a DMIPS/MHz of 1.89, and a CPI of 1.13, showcasing remarkable capabilities for an embedded processor.

翻译：对高能效与高性能嵌入式系统的需求推动了新型硬件架构的发展，近似计算等概念应运而生。本文提出一种名为“phoeniX”的新型可重构嵌入式平台，该平台采用标准RISC-V指令集架构，在保持应用层可接受精度的同时最大化能效。该平台支持在核心层级集成具有不同结构、精度与时序的近似电路，且无需修改核心（尤其是控制逻辑）设计。平台引入了创新的控制特性，允许根据具体应用需求在精度与能耗之间进行可配置的权衡。为评估平台效能，我们在图像处理及Dhrystone基准测试等一系列应用上进行了实验。该核心及其原始执行引擎在45纳米CMOS工艺下占用面积为0.024平方毫米，在1.1V工作电压下平均功耗为4.23毫瓦，在620MHz频率下每操作平均能效为7.85皮焦。该可配置平台采用高度优化的三级流水线RV32I(E)M架构，其DMIPS/MHz达到1.89，CPI为1.13，展现了嵌入式处理器卓越的性能表现。