A ternary content-addressable memory (TCAM)-based hardware called nonvolatile “multi-functional CAM (MF-CAM)” is proposed for an ultra-low-energy “full-text search” system in recent data centers. The proposed nonvolatile MF-CAM-based full-text search engine can perform parallel comparison while eliminating leakage energy by hierarchical power gating. By the massively parallel comparison with the hierarchical power gating, energy consumption of the proposed search engine is reduced within 1% in comparison with the conventional CPU-based full-text search system, where repetitive comparisons between the CPU and a memory consume much energy.