Based On Dsp For Direct Digital Frequency Synthesis (dds) Technology

Direct Digital Synthesis (DDS) consists of the phase accumulator, the sine look-up table,the digital to analogy converter and the low band filter.The generated signals have advantages of high frequency resolutions, fast frequency switching speed,low phase noise,the ability to switch frequencies while maintaining constant phase.Now it has been widely used in the fields of radar, communication, apparatus,etc.Firstly, the thesis compares the features of various frequency synthesis methods, studies the structure and function of ADI's AD9854. Then analyses the spectrum of output siginal and put forward some improvement measures. The thesis simulates and tests the Evaluation Board under AD985254 Customer Evaluation soft. The single-tone, FSK, CHIRP modulation simulation are also completed.A direct digital synthesizer board based on DSP processors TMS320VC5410 of TI and AD9854 has successfully designed. such as memory circuit, power circuit,clock circuit and other external interface circuit.The entire system software has been design completely including the DDS drivers programme, the sine wave,FSK,CHIRP and Bootloader.This thesis focuses on how to design the bootloader. The programme has successfully been burned into FLASH memory by peripheral bootloader. Finally, by testing and debugging on DDS prototype, the sine wave,FSK,CHIRP were achieved. It proved that the design of system is effective.