The Design of Direct Digital Synthesizer Based On Cordic Algorithm and FPGA Implementation

Currently, there are many methods that can implement direct digital synthesizer (DDS) including ROM look-up table method, Cordic algorithm and so on.Traditional DDS usually adopts the method of look-up table, which needs ROM to save a lot of waveform data.But the frequency resolution of DDS depends on how many ROM can save.Obviously the more data ROM can save, the better frequency resolution will be.Thus it takes the more ROM resources and the higher power dissipation while it gets the lower reliability and the slower conversion speed.However, Cordic algorithm use the method of iteration, which can generate high-resolution local oscillator signal through the shift, accumulation and subtraction operation.Compared with ROM look-up table, it reduces the occupation of the resources of ROM substantially.Therefore, this paper use Cordic algorithm to design DDS.At the same time, the Cordic algorithm is programmed into the FPGA device, which can generate sine and cosine waveform.The frequency and amplitude of waveform can be adjusted by the host computer.Then the desired waveform is simulated in Modelsim and Chipscope platform.As a result, the function of waveform is debugged and verified in hardware platform successfully.