一种基于CORDIC算法的坐标变换电路

在超声医疗仪器（如B超）的数字图像处理中，将超声探头所获得的极坐标形式的图像信号实时地在直角坐标系统的显示器上显示出来，图像信号从极坐标变换到显示系统的直角坐标是系统性能的关键。本文在介绍了CORDIC（Coordinate rotation digital computer)算法的基础上，提出子一种基于CORDIC算法的流水线型的坐标变换电路，随后给出了该变换电路用FPGA实现的过程和硬件仿真结果。硬件仿真结果表明，它的精度高、误差小。与其他方法相比，具有结构简单，易于VLSI实现等优点。

A CORDIC-Based Coordinate Transform Circuit

In digital image processing of ultrasonic medical instruments, such as B scanner, in order to display the image signals received in the shape of polar coordinate in real time, because the monitor is a coordinate system, the coordinate transform of image signals is the key factor of system performance. In this paper, a pipelined CORDIC based coordinate transform circuit is described. First, CORDIC algorithm is presented and its theory is analyzed, then the procedure of using FPGA for implementation is described in detail, and some simulational results are listed in the end. The results indicate that the resolution of this circuit is high, and error is small. Compared with the other ways, the circuit is very simple, but can make a better performance easy to be implemented by VLSI, therefore, it can process data more rapidly because its pipelined architecture.