Hardware Approach of a Multipurpose Finite Impulse Response Filter for Real-Time Filtering Applications

Problem statement: Finite Impulse Response (FIR) filters are widely used in various DSP applications. The design of digital FIR filters is a very basic problem in digital signal processing. A FIR filter with multiple operation capability is certainly very useful for any real-time filtering applications. This article presents a multipurpose FIR filter design modeled by the hardware description language VHDL for real-time filtering application. Approach: The VHDL has its concept of concurrency to cope with the parallelism of digital hardware. The novel feature is the capability of the design to accomplish up to 127variable filter order and an arbitrary filter frequency response. The coefficients are calculated by Hamming windowing technique. Basing on selection embedded in the design, the model is able to execute highpass, lowpass, bandstop and bandpass filtering operations. It is set at 8-bit signed data processing. To filter the input data in time domain, Linear Constant Coefficient Difference Equation (LCCDE) is used by the filter. Results: The design outputs are validated through simulation and compilation. The output results are also compared with the MATLAB implemented calculated output results to test the correctness that proves the effectiveness of the design. Conclusion: With the capability of filtering signal in real time mode utilizing arbitrary filter shape, the multipurpose filter proves to be versatile.