By: EDN Asia Technical Staff
Published: Q2 2021
In the high-stakes world of ASIC and FPGA design, the bridge between RTL (Register-Transfer Level) fantasy and gate-level reality is synthesis. For over three decades, Synopsys’ Design Compiler has been that bridge—the de facto standard for logic synthesis. The 2021 release (part of the 2021.03-SP3 family) didn’t reinvent the wheel; instead, it sharpened the axe. This feature explores the critical updates, workflow optimizations, and a hands-on tutorial to get you from Verilog to a timing-closed netlist faster than ever.
check_timing. It prevents false paths from ruining your chip.compile_ultra if you have the license; it handles datapaths intelligently..ddc file—it preserves all intermediate states for debugging.For further learning, consult the dc_ug.pdf (User Guide) from the 2021 documentation suite, specifically Chapters 6 (Constraints) and 11 (Compile Strategies).
Good luck with your synthesis!
This tutorial provides a condensed guide to using the Synopsys Design Compiler (DC) for RTL synthesis, based on standard workflows and features relevant to the 2021 period, including newer NXT technologies. 1. Introduction to Design Compiler
Design Compiler is the industry-standard RTL synthesis solution. It transforms Register Transfer Level (RTL) code (Verilog or VHDL) into an optimized gate-level netlist by mapping the design to a specific standard cell library. Key 2021+ Features:
Design Compiler NXT: Offers 2X faster runtime, improved power (up to 12% lower), and "cloud-ready" automated flows.
Topographical Technology: Predicts timing and area within 10% of post-layout results, reducing iterations between synthesis and physical design.
Multicore Scaling: Optimized for quad-core and multicore servers for faster synthesis. 2. Environment Setup
Before launching the tool, you must configure your environment and setup files.
Project Directory: Create a dedicated directory for your synthesis run to house log files and reports.
Setup File (.synopsys_dc.setup): This critical file tells DC where to find libraries. Key variables include: search_path: Directories for RTL and libraries.
target_library: The .db files from your foundry (e.g., 65nm, 14nm) used for mapping.
link_library: Libraries used to resolve references (usually includes the target library and any RAMs/IP).
symbol_library: Used for graphical schematic viewing (.sdb files). 3. The Synthesis Workflow
Synthesis follows four primary stages: Analyze & Elaborate, Apply Constraints, Optimization, and Reporting. Step 1: Analyze & Elaborate
Design Compiler: Timing, Area, Power, & Test Optimization | Synopsys
Synopsys Design Compiler Tutorial 2021: A Comprehensive Guide
Synopsys Design Compiler is a widely used Electronic Design Automation (EDA) tool for designing and optimizing digital circuits. It is a crucial step in the VLSI design flow, allowing designers to convert RTL (Register-Transfer Level) code into a gate-level netlist. In this tutorial, we will provide a comprehensive overview of Synopsys Design Compiler, covering its features, setup, and usage.
What is Synopsys Design Compiler?
Synopsys Design Compiler is a software tool that enables designers to create, optimize, and verify digital circuits. It supports a wide range of design styles, including ASIC (Application-Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and SoC (System-on-Chip) designs. The tool provides a comprehensive set of features for:
Key Features of Synopsys Design Compiler
Setting up Synopsys Design Compiler
To use Synopsys Design Compiler, you need to:
Basic Design Flow using Synopsys Design Compiler
The basic design flow using Synopsys Design Compiler involves:
Synopsys Design Compiler Tutorial 2021: Step-by-Step Guide synopsys design compiler tutorial 2021
Here is a step-by-step guide to get you started with Synopsys Design Compiler:
Step 1: Install and configure Synopsys Design Compiler
Step 2: Prepare your design
Step 3: Read and elaborate design
Step 4: Optimize design
set_clock_gating and set_power_gatingStep 5: Analyze design
Step 6: Write design
Conclusion
In this tutorial, we provided a comprehensive overview of Synopsys Design Compiler, covering its features, setup, and usage. We hope this tutorial has provided a solid foundation for designing and optimizing digital circuits using Synopsys Design Compiler. With practice and experience, you can master the tool and create efficient digital designs.
Additional Resources
For more information on Synopsys Design Compiler, refer to:
What's Next?
In our next post, we will provide a more advanced tutorial on Synopsys Design Compiler, covering topics such as:
Stay tuned for more updates on Synopsys Design Compiler and VLSI design!
The Synopsys Design Compiler (DC) is the industry-standard tool for logic synthesis, transforming high-level RTL (Verilog/VHDL) into an optimized gate-level netlist. 🛠️ Environment Setup
Before starting, ensure your Linux environment is configured to locate the Synopsys binaries and licenses.
Initialize Environment: Source your tool setup script (often provided by your CAD manager).
Working Directory: Create a dedicated folder for each project to manage generated files.
Setup File: Ensure a .synopsys_dc.setup file exists in your home or project directory. This defines: Search Path: Where DC looks for libraries and RTL.
Target Library: The .db file containing standard cell timing/power data (e.g., 14nm, 32nm).
Link Library: Typically includes the target library and any RAM/IP models. 🔄 The 4-Step Synthesis Flow Synthesis follows a structured path from code to gates. 1. Read & Elaborate
DC parses your HDL and creates an internal "GTECH" (generic technology) representation.
Command: read_verilog design.v or analyze followed by elaborate.
Verification: Check for "unresolved references" which indicate missing modules. 2. Apply Constraints
Define your "Design Intent" using Synopsys Design Constraints (SDC). Synopsys Tutorial: Using the Design Compiler - s2.SMU
A tutorial on Synopsys Design Compiler (DC) for 2021 focuses on the industry-standard logic synthesis flow, transforming high-level Register Transfer Level (RTL) code into an optimized gate-level netlist. Using modern features like Topographical technology, designers can achieve timing and area results within 10% of post-layout physical implementation. 1. Environment Setup Mastering the Silicon Canvas: A Deep Dive into
Before launching the tool, you must define your technology libraries and search paths. This is typically done in a .synopsys_dc.setup file located in your working directory. Search Path: Tells DC where to find RTL and library files.
Target Library: The standard cell library (.db) used for mapping logic.
Link Library: Includes the target library plus any RAM or IP macros; the * symbol ensures DC searches its own memory first. 2. Invoking the Tool Design Compiler can be run in two primary modes: Design Compiler: Timing, Area, Power, & Test Optimization
Synopsys Design Compiler (DC) is the industry-standard tool for logic synthesis, converting Register-Transfer Level (RTL) code into a technology-specific gate-level netlist. This 2021 tutorial outlines the essential flow for high-performance digital designs using dc_shell or the Design Vision GUI. 1. Preparation and Environment Setup
Before starting, ensure you have the RTL code, standard cell libraries, and a Synopsys Design Constraints (SDC) file.
Setup File: Create a .synopsys_dc.setup file in your working directory to define search paths and technology libraries.
target_library: The physical library containing standard cells for mapping (e.g., tcbn65lp.db).
link_library: Includes the target library plus any pre-compiled macros or memory.
search_path: Directories where the tool looks for RTL and library files. 2. Reading and Elaborating the Design
The synthesis process begins by loading your HDL (Verilog/VHDL) files into memory.
Analyze: Checks the RTL for syntax errors and creates intermediate files in the work library. analyze -format verilog top_module.v sub_module.v Use code with caution.
Elaborate: Builds the design hierarchy and identifies generic logic. elaborate top_module Use code with caution. 3. Applying Design Constraints
Constraints guide the optimization process by defining timing and physical limits.
Clock Definition: The most critical constraint, defining the period and uncertainty. create_clock -period 10 -name my_clk [get_ports clk] Use code with caution.
Input/Output Delays: Accounts for delays outside the current module.
set_input_delay 2.0 -clock my_clk [all_inputs] set_output_delay 1.5 -clock my_clk [all_outputs] Use code with caution.
Design Rules: Limits on fan-out, transition time, and capacitance. 4. Logic Optimization and Compilation
This step transforms the generic logic into actual gates from your target library while optimizing for area, power, and speed. Basic Compile: Use compile for standard designs.
Advanced Optimization: Use compile_ultra for high-performance designs requiring advanced features like boundary optimization and register retiming. compile_ultra -gate_clock Use code with caution. 5. Analyzing Results and Exporting
After synthesis, verify if the design meets its targets through generated reports. What is Synthesis? – How it Works | Synopsys
Synopsys Design Compiler (DC) converts high-level RTL (Verilog/VHDL) into optimized gate-level netlists, utilizing Topographical Mode for accurate, pre-layout timing and area estimation. The synthesis flow involves setting up technology libraries, applying Synopsys Design Constraints (SDC), compiling for optimization, and verifying with timing and power reports. For a detailed tutorial on the synthesis process, see this guide. Design Compiler: Timing, Area, Power, & Test Optimization
Mastering Digital Synthesis: A Synopsys Design Compiler Tutorial (2021 Edition)
In the world of VLSI, Synopsys Design Compiler (DC) remains the industry standard for logic synthesis. Whether you are a student or a professional engineer, mastering DC is essential for transforming high-level RTL (Verilog/VHDL) into an optimized gate-level netlist.
This 2021 tutorial focuses on the modern Topographical Mode and the core commands needed to navigate the synthesis flow effectively. 1. Understanding the Synthesis Flow
Synthesis is not just "translating" code. It is an optimization process that balances the PPA trinity: Power, Performance, and Area. The basic workflow involves:
Translation: Converting RTL to an unoptimized boolean representation (GTECH). Key Takeaways for 2021:
Optimization: Mapping GTECH to specific cells from your Target Library.
Mapping: Finalizing the gate-level netlist based on constraints. 2. Setting Up Your Environment
Before launching DC, you must define your library paths. This is typically done in a .synopsys_dc.setup file in your home directory or project folder.
# Setup Variables set link_library "* standard_cell_lib.db" set target_library "standard_cell_lib.db" set symbol_library "standard_cell_lib.sdb" set search_path ". /path/to/libraries /path/to/rtl" Use code with caution.
Target Library: The physical cells the tool will use to build your design.
Link Library: Used to resolve references (e.g., pre-existing IP blocks or pads). 3. Loading the Design
You can use read_verilog or the modern analyze and elaborate flow. The latter is preferred as it allows for better error checking and parameter passing.
# Analyze the RTL (Checks for syntax) analyze -format verilog my_design.v sub_module.v # Elaborate (Builds the generic technology-independent design) elaborate my_design # Set the current design context current_design my_design Use code with caution. 4. Applying Constraints (The SDC File)
Design Compiler is "constraint-driven." If you don't tell it how fast the design should be, it won't optimize for speed. These are typically saved in a Synopsys Design Constraints (SDC) file. The Clock:
create_clock -name my_clk -period 10 [get_ports clk] set_input_delay 2.0 -clock my_clk [all_inputs] set_output_delay 1.5 -clock my_clk [all_outputs] Use code with caution. Design Environment:
set_max_area 0 ;# Tells DC to make the design as small as possible set_load 0.5 [all_outputs] Use code with caution. 5. Running Compilation
In 2021, most designs use Design Compiler Graphical or Topographical mode. This mode uses physical data (like floorplan info) to predict wire delays more accurately than the old "Wire Load Models."
# Basic compile compile # For better results in modern nodes (Topographical) compile_ultra Use code with caution.
compile_ultra performs high-effort optimizations, including register retiming and advanced arithmetic optimization. 6. Analyzing Results (Reporting)
Once the synthesis is finished, you must verify if your constraints were met. Timing: report_timing (Check for Setup/Hold violations). Area: report_area (Check gate count and physical size). Constraint Violations: report_constraint -all_violators. 7. Exporting the Netlist
The final output is a gate-level netlist and an updated SDC file, which are then passed to Place and Route (P&R) tools like IC Compiler II.
write -format verilog -hierarchy -output "my_design_netlist.v" write_sdc "my_design_final.sdc" Use code with caution. Pro-Tips for 2021 Synthesis:
Check for "Unresolved References": Always run link after elaboration to ensure all modules are found.
Avoid "Dont_Touch": Be careful using set_dont_touch on modules, as it prevents DC from optimizing across boundaries.
Check Design: Use check_design before compiling to find unconnected wires or multiple drivers.
By following this flow, you can ensure that your RTL is transformed into a robust, high-performance netlist ready for physical implementation.
Do you have a specific RTL module or library file you're trying to synthesize right now?
This is a comprehensive guide to Synopsys Design Compiler (DC), tailored for a 2021 context (covering the J-2014.09 through J-2015 through 2020/2021 environments often found in university and corporate servers).
This guide moves from foundational concepts to advanced constraint scripting, covering the synthesis flow used in industry standard ASIC design.
mkdir -p ./reports
compile CommandThe standard compile command performs logic optimization and technology mapping.
# Basic compilation
compile
# Don't optimize area beyond 95% of initial estimate set_max_area 0------------------------------------------------------
4. Constraint Report
report_constraint -all_violators > reports/violators.rpt