在工业控制算法中,数学函数的计算往往需要大量的时钟周期,会影响算法的性能。本文对相关数学函数计算方法进行深入分析和方案对比,设计了一种适合硬件电路实现的基于Remez算法的分段查表多项式拟合方法来计算浮点数学函数,同时实现了相应的硬件电路以RISC-V自定义指令的方式与RISC-V处理器内核紧耦合。实验结果表明,与无自定义扩展指令相比,处理器计算数学函数的延迟减小了93.62%。相较于CORDIC指令集计算数学函数的方法,计算延迟减小了79.83%。这一成果为低成本、高实时性要求的RISC-V架构的嵌入式微处理器提供了新的思路和解决方案。

In industrial control algorithms, the calculation of mathematical functions typically requires a large number of clock cycles, affecting the performance of the algorithms. This paper conducts an in-depth analysis and comparison of related methods for calculating floating mathematical functions, and designs a piecewise table lookup polynomial fitting method based on the Remez algorithm. This method is suitable for hardware circuit implementation to calculate mathematical functions. At the same time, the corresponding hardware circuits are implemented in the form of RISC-V custom instructions, closely coupled with the RISC-V processor core. The experimental results show that compared with no custom extension instructions, the processor's delay in calculating mathematical functions is reduced by 93.62%. Compared with the method of calculating mathematical functions using the CORDIC instruction set, the calculation delay is reduced by 79.83%. This achievement provides new ideas and solutions for RISC-V architecture embedded microprocessors with low-cost, high real-time requirements.