global convergence analysis of mixed-signal systems
This paper proposes two practical approaches to address global convergence failures, commonly encountered in mixed-signal systems in which analog and digital components closely interact. That is, a nominally-working system may fail intermittently depending on its initial conditions upon start-up. The first approach uses a data clustering analysis and verifies global convergence with randomly-selected pilot simulations. The second approach adopts the practice of representing indeterminate states with X by defining its equivalent concept for analog based on entropy. With oscillator and phase-locked loop examples, it is demonstrated that the proposed approaches can effectively detect the failures and guide designers where to add more resets to prevent them.
global convergence analysis formal verification analog/mixed-signal systems