Performance Screening Using Functional Path Ring Oscillators

The testing of integrated circuits is an important topic, particularly in safety-critical applications. This is especially true for microcontrollers (MCUs) used in the automotive industry. A critical test is the performance screening in which the maximum clock frequency of the MCU is determined. For this performance screening, indirect monitors, such as ring oscillators (ROs), are used. This article presents a holistic overview of the functional path RO from the pre-silicon to the post-silicon. The implementation of such ROs is presented, as the associated advantages in terms of area consumption, leakage, and routing. In the post-silicon phase, the functional path RO frequencies are correlated with the MCU performance using machine learning approaches.