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- Fault Models<\/strong> \u2014 Patterns must cover a growing menu of fault models: stuck-at, transition delay, cell-aware, path delay, IDDQ, and more. Each model targets different defect scenarios, and each demands its own pattern set and verification.<\/li>\n\n\n\n
- Timing Corners<\/strong> \u2014 Patterns must meet timing requirements across slow, fast, and multi-corner conditions. A pattern that passes at one corner may fail at another.<\/li>\n\n\n\n
- Test Modes<\/strong> \u2014 Scan, BIST, JTAG, and In-field use models each impose their own operational constraints. Every mode must be independently verified for correctness.<\/li>\n<\/ul>\n\n\n\n
Simulating large pattern sets at core, subsystem, and top level contexts to verify all of these requirements is time-consuming and resource-intensive<\/strong>, and the volume of simulation required continues to grow. In many programs, pattern simulation becomes a bottleneck that sits squarely on the critical path to tapeout. Teams are forced to make uncomfortable trade-offs: simulate fewer patterns and accept risk, or simulate more, reducing risk but incurring schedule pressure and additional cost.<\/p>\n\n\n\n
Neither option is good enough.<\/p>\n\n\n\n
The intersection of functional and DFT verification: It’s not just about patterns<\/h3>\n\n\n\n
Scan dump, High-Bandwidth IJTAG, and In-System Test are just three examples of new innovations coming to market under the purview of DFT teams. Each new innovation incurs a new verification objective. <\/p>\n\n\n\n
The Solution: Questa One DFT Verification | Tessent<\/h2>\n\n\n\n
This is where Questa One DFT Verification<\/strong>, combined with Tessent<\/strong>, changes the game entirely.<\/p>\n\n\n\n
![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/54\/2026\/03\/dft_blog-1024x411.png\")
<\/figure>\n\n\n\nTogether, it delivers the\u00a0industry’s most comprehensive and performant DFT simulation solution, purpose-built to address the DFT verification pain points. These solutions ranging from static\/formal, simulation, and debug, integrate the context of DFT to deliver value throughout the DFT lifecycle. Integrations with Tessent ensure a seamless workflow from traditional DFT activities (Test IP insertion, ATPG, etc…) and the corresponding verification activity.<\/p>\n\n\n\n
Industries fastest DFT simulator<\/h3>\n\n\n\n
Speed matters. Questa One DFT Verification delivers orders of magnitude performance advantage over existing solutions for DFT pattern simulation. Teams can now simulate larger pattern sets, in less time, with fewer compute resources. The pattern signoff bottleneck becomes manageable rather than paralyzing.<\/p>\n\n\n\n
Seamless Tessent Integration<\/h3>\n\n\n\n
The native integration between Questa One DFT simulation and Tessent creates a seamless flow from pattern generation to simulation. Manual handoffs between tools are reduced, potential errors at tool boundaries are eliminated, and engineers spend their time solving problems, not managing file formats and infrastructure.<\/p>\n\n\n\n
Beyond Pattern Signoff: Fault Simulation, In-System Verification, and Formal Analysis<\/h3>\n\n\n\n
Comprehensive DFT Verification demands more than pattern signoff alone. Questa One DFT Verification addresses the full breadth of DFT verification challenges through three tightly integrated and complementary capabilities, each targeting a distinct layer of the verification problem, and together delivering a defense-in-depth approach to identify issues as early as possible.<\/p>\n\n\n\n
Reduce Program Cost. Reduce Tapeout Risk.<\/h2>\n\n\n\n
The business case is clear:<\/p>\n\n\n\n
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- Early issue detection<\/strong> means problems are found when they’re cheap to fix, not after masks are cut<\/li>\n\n\n\n
- Faster simulation<\/strong> means less compute spend and reduced schedule pressure<\/li>\n\n\n\n
- Comprehensive signoff<\/strong> means fewer test escapes and a lower probability of costly silicon respins<\/li>\n\n\n\n
- Seamless integration<\/strong> means less engineering time lost to flow management<\/li>\n<\/ul>\n\n\n\n
The combination of Questa One DFT Verification and Tessent protects your investment and gives your team the confidence to tape out on schedule, with quality.<\/p>\n\n\n\n
Learn More<\/h2>\n\n\n\n
- Faster simulation<\/strong> means less compute spend and reduced schedule pressure<\/li>\n\n\n\n
- Timing Corners<\/strong> \u2014 Patterns must meet timing requirements across slow, fast, and multi-corner conditions. A pattern that passes at one corner may fail at another.<\/li>\n\n\n\n