Synopsys Timing Constraints And Optimization User Guide 2021 ~upd~

In modern digital design, achieving aggressive Power, Performance, and Area (PPA) targets requires meticulous control over timing. The serves as a foundational roadmap for designers using tools like Design Compiler (DC) and PrimeTime, providing the methodologies necessary to transition from RTL to GDSII without sacrificing performance.

: set_max_area , set_max_dynamic_power , and set_max_leakage_power are used to drive the tool toward smaller or more efficient implementations.

set_output_delay -max 0.5 -clock SYS_CLK [get_ports data_out] set_output_delay -min -0.2 -clock SYS_CLK [get_ports data_out] Use code with caution. 5. Advanced Timing Exceptions

At the heart of the methodology described in the user guide is the Synopsys Design Constraints (SDC) format. SDC is the industry-standard language for specifying a design's timing requirements. The guide states that it is used for describing the design requirements for timing, power, and area, and is the most common format for tools performing synthesis, STA, and place-and-route.

Modern flows emphasize early constraint verification to avoid late-stage silicon failure: Timing Constraints Manager | Synopsys synopsys timing constraints and optimization user guide 2021

The guide warns users about the dangers of improper handoff. It stresses that every SDC command must be verified. A common practice in the industry is to run check_timing in PrimeTime after loading the SDC to identify unconstrained paths, input ports with no delay, or incorrectly generated clocks.

set_clock_uncertainty -setup 0.15 [get_clocks SYS_CLK] set_clock_uncertainty -hold 0.05 [get_clocks SYS_CLK] Use code with caution.

Ensures that the data does not change too quickly after a clock edge, which would corrupt the captured value. Hold violations are often caused by excessively short combinational logic paths.

Not all paths in a design should be analyzed with default single-cycle timing. The 2021 guide provides commands for timing exceptions: set_output_delay -max 0

# Specifies that the external device requires the signal 0.5ns before the next clock edge set_output_delay -max 0.5 -clock sys_clk [get_ports data_out] Use code with caution. 4. Advanced Timing Exceptions

The 2021 guide reinforces a golden rule of digital design: a design is only as good as its constraints. The documentation spends significant time refining the usage of create_clock and create_generated_clock , emphasizing that over-constraining or under-constraining are equally fatal to design integrity.

The Synopsys Timing Constraints and Optimization User Guide (2021)

Fine-tune constraints to explore different trade-offs between performance, power, and area. SDC is the industry-standard language for specifying a

: Automatically adding buffers to long wires to reduce interconnect delay and fix high fan-out nets.

PrimeTime is the industry standard for sign-off. The 2021 guidelines emphasize using PrimeTime (or PrimeTime SI) for final verification.

What are you using (e.g., Wireload models or Graphical/Topographical mode)?