Energy-aware architectures for a real-valued FFT implementation

Energy-aware design is highly desirable for systems that encounter a wide diversity of operating scenarios. This is in contrast to traditional low power design for the worst case scenario, which may not be globally energy efficient. Energy-aware design focuses on enabling architectures which scale down energy as quality requirements are relaxed. A new energy-scalable system design methodology is proposed for a Real-Valued FFT processor which supports variable bit precision (8 and 16-bit precision) and variable FFT length (128- 512 point). Two energy-aware architectures, Ensemble of Point Solutions method and Reuse of Point Solutions method, are described and evaluated. Simulated and measured results show a 66% energy savings for 8-bit datapath and 52% savings for 128-point FFT length over a non-scalable approach.