Questa Sim2025.2

Questa Sim 2025.2 Overview

Questa Sim is a flagship electronic design automation (EDA) tool from Siemens EDA, renowned as the gold standard for mixed-language simulation and verification of complex ASIC, SoC, and FPGA designs. It supports Verilog, SystemVerilog, VHDL, and SystemC, enabling high-performance simulation, debugging, and coverage analysis. With aggressive optimization algorithms, it delivers up to 10x faster RTL simulation speeds compared to traditional tools, while maintaining a unified database for seamless debug and coverage across multi-core environments.

As of October 13, 2025, Questa Sim has evolved significantly with the launch of Questa One Sim in June 2025, which serves as the next-generation foundation for Questa-based simulation. This update addresses the escalating complexities of 3D-ICs, chiplet architectures, and software-defined systems by integrating AI-driven automation, faster engines, and unified functional/fault simulation. The “2025.2” designation likely refers to a mid-2025 patch or minor release within the Questa One ecosystem (e.g., post-v1.0 enhancements), focusing on refined performance and ecosystem integrations. If this is a specific internal or beta version, Siemens support can provide exact details.

Key Features of Questa Sim (2025.2 / Questa One Sim)

• High-Performance Simulation: Multi-core partitioning for parallel execution, with up to 2.5x faster Verilog/VHDL simulations. Supports automated stimuli generation via SystemVerilog/SCV libraries for efficient testbench automation.
• AI-Enhanced Productivity: Advanced constraint solvers accelerate coverage closure, reducing project timelines and compute resources. Protocol-aware debug and coverage analytics streamline verification for PCIe, CXL, and HBM interfaces.
• Fault and Safety Analysis: Questa One Sim FX introduces scalable concurrent fault simulation to validate resilience in safety-critical designs, grading undetected faults for better defect coverage.
• Unified Verification Flow: Integrates with Questa CDC for dynamic metastability injection, profiler for regression-wide hotspot analysis, and DFT acceleration (in partnership with Tessent) to cut verification time from weeks to days.
• Ecosystem Compatibility: Reuses testbenches and stimuli across Questa One, Veloce CS emulation, and prototyping systems. Supports AArch64 architectures for cloud deployments like Microsoft’s Azure Cobalt 100, yielding up to 20% additional performance gains.

What’s New in 2025.2 / Questa One Era?

• Launch and Availability: Unveiled at User2User Munich in May 2025 and generally available since June, Questa One unifies simulation, formal verification, and IP under one platform to close verification productivity gaps.
• Performance Benchmarks: Early adopters like MediaTek report reduced regression times and cost-efficiency in large EDA workloads. Microsoft notes DFT simulation speedups slashing verification from weeks to days.
• AI and Automation Focus: Built-in AI/ML streamlines redundant test case removal and faster coverage, tailored for generative AI and data center workloads.
• Upcoming Events: Siemens Verification Academy hosts webinars on Questa topics through late 2025, including simulation updates on October 23 (SafeSPI) and Questa Design Solutions on October 8.