: Start with "loose" constraints to explore the design space, then tighten them as the physical floorplan matures.
The 2021 documentation introduced enhanced support for advanced process nodes (7nm and below) where parasitic effects are dominant.
: A dedicated environment to verify, generate, and manage SDC files throughout the design cycle to prevent "garbage in, garbage out" scenarios. 5. Best Practices for Timing Closure To achieve faster turnaround times, the guide recommends: synopsys timing constraints and optimization user guide 2021
: Techniques like Parametric On-Chip Variation (POCV) allow for more precise modeling of local process variations, reducing unnecessary design pessimism.
: When the standard single-cycle timing model is too restrictive, exceptions are used: : Start with "loose" constraints to explore the
: Moving registers across combinational logic boundaries to balance path delays without changing the design’s functionality.
: Leveraging clock gating and multi-threshold CMOS (MTCMOS) cells to reduce both dynamic and leakage power during the timing-closure process. 4. Advanced Features in the 2021 Release : Leveraging clock gating and multi-threshold CMOS (MTCMOS)
: Users are guided on choosing between Graph-Based Analysis (GBA) for speed and Path-Based Analysis (PBA) for higher accuracy during the final signoff stages. 3. Optimization Strategies
: These account for the propagation delays external to the chip. The guide details how to use set_input_delay and set_output_delay to model the environment at the chip’s boundary.
: Use report_timing with detailed options to identify if a violation is caused by logic depth, high fan-out, or poor placement.