Timing Error Prediction AVFS With Detection Window Tuning for Wide-Operating-Range ICs

In-situ timing monitoring-based adaptive voltage frequency scaling (AVFS) is effective in eliminating the timing margin. However, for wide-operating-range applications, one big challenge is that severe process, voltage, and temperature variations causes varying need for detection window. Therefore, a timing error prediction based AVFS method is proposed with on-chip detection window tuning to solve this problem. In addition, to cope with the area overhead problem, an activation-oriented monitoring paths selection method is proposed to decrease the insertion rate. Implemented on a 45-nm CMOS Bitcoin miner chip working across 0.6 V-1.1 V, it increases the throughput by 190.8%, 83.3%, 67.9%, and 25.4% at 0.6 V, 0.72 V, 0.9 V, and 1.1 V, respectively, for a typical die at 25 °C, compared to baseline frequencies. Measurement results demonstrate that our AVFS system is suitable for wide-operating-range applications.