This guide is structured to support the entire chip implementation process, as detailed in the table below:
Synopsys Timing Constraints And Optimization. User Guide. Mastering Synopsys Timing Constraints and Optimization: A User's. Guide. uml.edu.ni Synopsys Timing Constraints And Optimization User Guide
Best Practice: Define all base clocks at the top level and ensure create_generated_clock handles internal clock derivation.
Defining clocks derived from main clocks (e.g., PLL outputs). synopsys timing constraints and optimization user guide 2021
set_clock_groups -asynchronous -group CLK_CORE -group CLK_USB, CLK_PCIE Use code with caution. 5. Optimization Methodologies in Design Compiler
: Operates on the High-Level Design (HDL) description. It performs resource sharing (e.g., sharing an adder), selecting arithmetic architectures, and macro generation.
These define how long external logic takes to deliver data to the chip ( Tincap T sub i n end-sub ) or accept data from it ( Toutcap T sub o u t end-sub This guide is structured to support the entire
Once an accurate SDC profile is established, Design Compiler executes multi-level optimization routines to map the RTL design into target library cells (gates) while respecting constraints. Optimization Phases
The content in this article is based on notes and summaries from that version. It is important for engineers to always refer to the latest official documentation for their specific tool version, as features and commands are continuously updated. Later versions, like the release used in some community resources, may include changes that supersede the 2021 guide.
To get the most out of Synopsys' timing constraints and optimization capabilities, designers should follow best practices: The default is "balanced
The 2021 guidelines emphasize that constraints should be . Over-constraining forces the tool to work unnecessarily hard, leading to bloated area and excessive power consumption. Under-constraining, conversely, leads to optimistic results that fail in silicon. 2. Defining the Clock Tree
Early detection of invalid or inconsistent constraints.
Do not use the default settings. The 2021 guide explicitly warns against using compile_ultra without the -timing_high_effort flag. The default is "balanced," which leaves 5-7% performance on the table.