The New Design and Verification Based on the Coordinate Rotation Digital Computer

摘要

The Coordinate Rotation Digital Computer (CORDIC) is an effective convergence algorithm that is used to compute many trigonometric functions using shifts and additions. However, it is difficult to be completely implemented in Integrated Circuit (IC) field because the CORDIC has six complex operating modes. Currently the shortcoming of CORDIC in the IC field are the low precision and the long calculation time so that it can't meet the actual needs. To over this, a new CORDIC algorithm that mainly adopts the iteration and the Looking-up Table (LUT) is introduced in this paper, which not only supports circular, linear and hyperbolic trigonometric function but it also has the interruption and overflowing functions. Most important is that it has liigher precision and faster calculation speed than the conventional design. For example, the calculation speed of new CORDIC is up to 120 MHz. Using this frequency, it takes about 40 clock cycles to finish a trigonometric calculation. Moreover, the random verification model is firstly applied in the process of CORDIC design, which may automatically verify the definition domains of all input data and quickly analyze the precision errors of the calculated results. Finally, the precision errors between the expected results and the actual results are fully recorded by the verification model.