The biggest challenge in using FPGA devices may be one of methodology. FPGA designers are familiar with HDL-based requirements-driven design methodologies for digital electronics. But how can requirements be expressed for a system that, while it contains digital elements, is fundamentally non-digital? Fortunately an executable HDL exists that extends the capabilities of the digital VHDL language. VHDL-AMS language is an undiscovered asset for FPGA designers - a powerful tool to define and verify requirements in a non-digital context.