2021 ((hot)) - Synopsys Timing Constraints And Optimization User Guide

: Techniques like Parametric On-Chip Variation (POCV) allow for more precise modeling of local process variations, reducing unnecessary design pessimism.

create_clock -name SYS_CLK -period 2.0 -waveform 0.0 1.0 [get_ports sys_clk] Use code with caution. -period 2.0 : Sets a 2.0 ns target (500 MHz).

This technical guide unpacks the foundational methodologies and implementation techniques outlined in the , focusing on Synopsys Design Constraints (SDC) generation, clock modeling, path exception handling, and synthesis optimization. 1. Understanding the Synopsys Timing and Optimization Flow

Once constraints are defined, the Synopsys optimization engine works to map logic gates efficiently while minimizing area, power, and timing violations. The Optimization Flow synopsys timing constraints and optimization user guide 2021

Limits the total capacitive load a single gate pin can drive to prevent signal degradation.

Fine-tune constraints to explore trade-offs between performance, power, and area.

# Allows data 3 full clock cycles to propagate from the multiplier inputs to outputs set_multicycle_path 3 -setup -from [get_pins mult_core/start_reg/Q] -to [get_pins mult_core/end_reg/D] # Corrects the hold relationship to align with the new setup definition set_multicycle_path 2 -hold -from [get_pins mult_core/start_reg/Q] -to [get_pins mult_core/end_reg/D] Use code with caution. 5. Synthesis and Optimization Methodologies : Techniques like Parametric On-Chip Variation (POCV) allow

Timing constraints are used to specify the timing requirements of a digital design. They define the relationships between signals and the timing relationships between different parts of the design. There are several types of timing constraints, including:

Beyond setup and hold timing, the tool must honor physical design rule constraints dictated by the semiconductor foundry. These take priority over performance optimization:

: Defining arrival times at input ports relative to a clock using set_input_delay Output Delays : Specifying required times at output ports using set_output_delay Port Attributes The Optimization Flow Limits the total capacitive load

For complex SoCs, Synopsys highlights the Timing Constraints Manager (TCM) , which automates the verification and promotion of constraints from IP to SoC levels.

A data pin of a sequential element or an output port. Setup vs. Hold Constraints