Abstract: Sine & cosine function is used broadly in engineering. Ordinarily, lookup-table algorithm implements easily, but a large amount of memory units are necessary and the contradiction between accuracy and the mount of memory units is acute. Traditional CORDIC（Coordinate Rotation Digital Computer） algorithm can achieve higher accuracy with less memory units, but needs more hardware resource and has long output delay. A new architecture combined with lookup-table and CORDIC algorithm is proposed. The design, simulation and hardware testing based on FPGA of the improved algorithm have been completed which indicates that it can achieve higher accuracy and lower output delay with less hardware resource and few memory units.

Key words: CORDIC algorithm, lookup-table, sine &, cosine function, Field Programmable Gate Array（FPGA）

摘要： 正余弦函数在工程实现中应用很广泛。常用的查找表方法实现简单，但占用存储器资源较多，计算精度与存储容量的矛盾比较突出；传统的CORDIC（坐标旋转数字计算）方法虽占用存储资源少，但硬件资源消耗大，且输出时延长。鉴于此，提出一种改进型的CORDIC算法，将查找表和CORDIC算法相结合，完成了该算法的设计仿真和基于FPGA的硬件测试；结果表明该算法能够利用少量硬件资源和部分存储资源，实现较高的计算精度和较低的输出时延。

关键词: CORDIC算法, 查找表, 正余弦函数, 现场可编程逻辑器件（FPGA）