The COordinate Rotation DIgital Computer or CORDIC is an iterative algorithm for computing vector rotation. It uses only shift-and-add operations that make it a popular choice for computing operations such as vector rotation, matrix, trigonometric, hyperbolic, logarithmic and exponential computations in embedded platforms. This paper gives a control perspective to the algorithm by describing it as a switched autonomous nonlinear discrete system. A Lyapunov function-based analysis for switched system is applied to show the stability of the system. This analysis provides a methodology to derive metrics for comparing various variations developed for reducing latency. Further, the switching behavior is analyzed and a novel architecture is developed for reducing latency without any compromise on the metrics. The hardware implementation of novel architecture is based on the attempt to unfold the conventional architecture by predicting the switching signal.

中文翻译：

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CORDIC 作为开关非线性系统

坐标旋转数字计算机或 CORDIC 是一种用于计算矢量旋转的迭代算法。它仅使用移位和加法运算，使其成为嵌入式平台中计算运算（例如矢量旋转、矩阵、三角、双曲线、对数和指数计算）的流行选择。本文通过将算法描述为切换的自主非线性离散系统，给出了该算法的控制视角。应用基于李雅普诺夫函数的切换系统分析来显示系统的稳定性。该分析提供了一种方法来导出用于比较为减少延迟而开发的各种变体的指标。此外，还分析了切换行为，并开发了一种新颖的架构，用于在不影响指标的情况下减少延迟。