Verification of analog/mixed-signal (AMS) circuits is complicated by the difficulty of obtaining circuit models at suitable levels of abstraction. We propose a method to automatically generate abstract models suitable for formal verification and system-level simulation from transistor-level simulation traces. This paper discusses the application of the proposed methodology to a switched capacitor integrator and PLL phase detector.
Analog-mixed signal (AMS) circuits are widely used in various mission-critical applications necessitating their formal verification prior to implementation. We consider modeling two AMS circuits as hybrid automata, particularly a charge pump phase-locked loop (CP-PLL) and a full-wave rectifier (FWR). We present executable models for the benchmarks in SpaceEx format, perform reachability analysis, and demonstrate their automatic conversion to MathWorks Simulink/Stateflow (SLSF) format using the HyST tool. Moreover, as a next step towards implementation, we present the VHDL-AMS description of a circuit based on the verified model.
Semi-formal verification of the steady state behavior of mixed-signal circuits by SAT-based property checking