Complex Analog/Mixed-Signal System-on-Chip Designs Questa ADMS gives designers a comprehensive environment for verifying complex analog/mixed-signal System-on-Chip designs. ADMS combines four high performance simulation engines in one efficient tool: Eldo® for general purpose analog simulations, Questa® for digital simulations, ADiT™ for fast transistor-level simulations and Eldo RF for modulated steady state simulation. Analog and mixed-signal SoC designs combine analog and digital content more tightly than ever before. They increasingly depend on integrated analog blocks such as A to D and D to A converters, phase-locked loops, and adaptive filters. This increased level of integration puts tremendous pressure on designers. Traditional design tool flows force designers to develop analog and digital subsystems in isolation, delaying the integration of these components until IC layout and the testing until after fabrication. Before Questa ADMS, AMS SoC design was a slow, expensive and error-prone process.