Challenges of using on-chip performance monitors for process and environmental variation compensation

Circuit monitoring techniques have been adopted widely to compensate for process, voltage, and temperature variations as well as power optimization of integrated circuits. For cost and complexity reasons, these techniques are usually implemented by means of performance monitors allowing fast performance evaluation during production. In this paper, we demonstrate the limitations of performance monitoring methodologies in terms of accuracy and effectiveness. Silicon measurements of a nanometric FD-SOI device show that the required design margin is above 10% of the clock cycle, which leads to unacceptable waste of power.