Near-Vt adaptive microprocessor and power-management-unit system based on direct error regulation

We present a co-design approach of a near-threshold voltage adaptive microprocessor and power-management unit (PMU). It consists of (i) a microprocessor with in-situ error detection and correction; (ii) an integrated 63-ratio switched-capacitor DC-DC converter; and (iii) an error-based controller which regulates the timing error rate of microprocessor directly instead of indirectly through regulating PMU output voltage. The measurement of the prototyped chips shows a significant improvement in system-level efficiency that considers both power conversion and consumption.