System level tools for DSP in FPGAs

Abstract

Visual data flow environments are ideally suited for modeling digital signal processing (DSP) systems, as many DSP algorithms are most naturally specified by signal flow graphs. Although several academic and commercial frameworks provide a high level of abstraction for modeling DSP systems, they have drawbacks as design tools for FPGAs. They do not provide efficient implementations, and their system behavior only approximates the hardware implementation. In this paper, we describe a software system that employs a visual data flow environment for system modeling and algorithm exploration. In this environment, the bit and cycle behavior of the FPGA implementation are manifest. By observing circuit behavior in the system environment, one obtains significant speed improvement over hardware simulation, while gaining substantial flexibility afforded by functional abstraction. In addition, the software automatically generates a faithful hardware implementation from the system model. Specific issues addressed include the mapping of system parameters into implementation (e.g., sample rates, enables), and implications of system modeling for testing (e.g., testbench generation).