Implementing Minimum-Energy-Point Systems With Adaptive Logic

Timing-error-detection (TED)-based systems have been shown to reduce power consumption or increase yield due to reduced margins. This paper shows that the increased adaptability can be a great advantage in the system design in addition to the well-known mitigated susceptibility to ambient and internal variations. Specifically, the design tolerances of the power management are relaxed to enable even greater system-level energy savings than what can be achieved in the logic alone. In addition, the system is simultaneously able to operate near the minimum error point. Here, the power management is a simplified dc-dc converter and the TED is based on time borrowing. The target application is a single-chip system on chip without external discrete components; thus, switched capacitors are used for the dc-dc. The system achieves 7.9% energy reduction at the minimum energy point simultaneously with a 36.4% energy-delay product decrease and a 15% increase in dc-dc efficiency. In addition, the effect of local variations on average system performance is reduced by 12%.