Emulation of analog audio circuits on FPGA using wave digital filters

Abstract

This paper presents a Wave Digital Filter (WDF) emulation system suitable for audio applications implemented on a Field Programmable Gate Array (FPGA). The WDF structures are programmed in the reconfigurable FPGA CompactRIO via LabVIEW. When the system runs in real-time, the circuit parameters are controlled and monitored via a graphical user interface on a host computer. A tone control and a three way crossover filter are presented as application examples. The WDF emulations are validated by measuring the signals from the FPGA I/O modules with a data acquisition system. Measurement results confirm the accuracy of the presented examples and the reliability of CompactRIO to perform WDF audio circuit emulations.