Towards an FPGA-Based Compilation Flow for Ultra-Low Latency Audio Signal Processing

Field Programmable Gate Arrays (FPGAs) have been increasingly used in recent years for real-time audio Digital Signal Processing (DSP) applications. They provide unparalleled performances in terms of audio latency and processing power. They can target extremely high audio sampling rates and their large number of General Purpose Inputs and Outputs (GPIOs) make them particularly adapted to the development of large scale systems with an extended number of audio inputs and outputs. On the other hand, programming them is extremely complex and out of reach to non-specialized engineers as well as to most people in the audio community. In this paper, we introduce a comprehensive FPGA-based environment for real-time audio DSP programmable at a high level with the FAUST programming language. Our system reaches unequalled latency performances (11.1 us round-trip) and can be easily controlled using both a software graphical user interface and a dedicated hardware controller taking the form of a sister board for our FPGA board. The implementation of the system is described in details and its performances are evaluated. Directions for future work and potential applications are presented as well.