FPGA implementation of dynamically tunable filters

Digital Signal Processing techniques are extensively used in a large number of applications such as communication and multimedia and filtering concepts are considered as one of the basic elements needed for digital signal processing. This has motivated the design of digital filters for digital signal processors (DSPs) and Field Programmable Gate Arrays (FPGAs) based system design. The cut-off frequencies of these filters vary based on the requirements of application. In this paper, FPGA implementation of dynamically tunable Finite Impulse Response (FIR) filter is proposed, wherein the cut-off frequency can be dynamically changed on-the-fly without any need to program the FPGA. The proposed work is carried out to design high pass, low pass, band pass and band stop filters. The performance of the filters designed is evaluated for direct form structure and optimized structure using Virtex-5 FPGA board.