Creating primary, generated, and virtual clocks to drive the sequential design.
The Synopsys Timing Constraints and Optimization User Guide 2021 also addresses common challenges and provides solutions:
When the design moves to physical implementation and signoff with , the timing constraints continue to guide the process. Engineers use PrimeTime, Synopsys' golden signoff-quality STA tool, to run the final, accurate timing checks before tapeout. It reads the design, parasitic information (like SPEF files), and the SDC constraints to ensure every timing path meets its requirements.
Only flatten modules that have high timing violations and minimal area impact. 5. Conclusion synopsys timing constraints and optimization user guide 2021
Models clock jitter (random phase variations) and skew (spatial distribution delay variations). This acts as a safety margin during optimization.
Utilize tools based on FishTail Technology to verify, generate, and manage SDC constraints automatically.
In the world of System-on-Chip (SoC) design, timing is not just a metric; it is the heartbeat of silicon functionality. As process nodes shrink to 7nm, 5nm, and beyond, the complexity of closing timing increases exponentially. For design engineers using Synopsys tools like Design Compiler or IC Compiler, the bible for navigating this complexity has long been the Timing Constraints and Optimization User Guide . Creating primary, generated, and virtual clocks to drive
An SDC file acts as the single source of truth throughout the digital design flow. The same constraints applied during logic synthesis in Design Compiler are passed downstream to physical implementation in IC Compiler II and final sign-off validation in PrimeTime. 2. Defining the Clock Network
This guide is structured to support the entire chip implementation process, as detailed in the table below:
Once constraints are defined, Synopsys Design Compiler (DC) uses sophisticated optimization techniques to meet those goals. 3.1. Logical Optimization It reads the design, parasitic information (like SPEF
Synopsys tools rely on the industry-standard format to understand the performance goals of your circuit. Without proper constraints, synthesis and implementation tools cannot optimize the logic effectively, leading to either unroutable congestion or missed performance targets. The Role of Static Timing Analysis (STA)
) cells for non-critical paths to reduce leakage power, and low- Vtcap V sub t cells on the critical path. 4. Best Practices for Timing Closure in 2021/2022
normalized slack = path slack / allowed propagation delay for path
Paths crossing between two entirely unrelated clock domains.
: As the official documentation for the creators of the SDC format, it provides the most accurate definitions of command syntax and tool behavior. Structured Methodology