FPGA Programming of Tunnable Waveform Generator

Field Programmable Gate Arrays are capable of accomplishing the goals of manufactured circuits while being able to be reconfigured in real time. One of the highlights to FPGA programming is the ability of executing commands in parallel as opposed to serial due to the hardware description nature of the code. Applications for FPGAs can be found in emulation of computer hardware, medical imaging, bioinformatics, and Digital Signal Processing. An example of signal processing is in the design of a tunable waveform generator capable of outputting sine waveforms up to 100 MHz and tuning amount of 0.5 Hz in either direction. Such a generator can be used in the simulation of lasers and laser control. Using the Xilinx Direct Digital Synthesis (DSS) IP, this is made possible. By using a reference clock of 268.75 MHz and a data word length of 29 bits, the tuning amount of 0.5 Hz can be obtained with minimal error while obeying the Nyquist sampling theorem. The data word length can also be increased for a more accurate tuning of up to 0.125 Hz in either direction. To improve on the design in the future, a digital Frequency Impulse Response filter can be created and configured to filter unwanted higher frequencies.