Intel® Quartus® Prime Pro Edition User Guide: Design Compilation

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Date 1/27/2022
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Document Table of Contents
Document Table of Contents x
1. Answers to Top FAQs 2. Design Compilation 3. Reducing Compilation Time 4. Intel® Quartus® Prime Pro Edition User Guide Design Compilation Archives A. Intel® Quartus® Prime Pro Edition User Guides
2. Design Compilation x
2.1. Compilation Overview 2.2. Using the Compilation Dashboard 2.3. Design Synthesis 2.4. Design Place and Route 2.5. Incremental Optimization Flow 2.6. Fast Forward Compilation Flow 2.7. Full Compilation Flow 2.8. Exporting Compilation Results 2.9. Integrating Other EDA Tools 2.10. Synthesis Language Support 2.11. Compiler Optimization Techniques 2.12. Synthesis Settings Reference 2.13. Fitter Settings Reference 2.14. Design Compilation Revision History
2.1. Compilation Overview x
2.1.1. Compilation Flows 2.1.2. Compilation Hierarchy
2.3. Design Synthesis x
2.3.1. Running Synthesis 2.3.2. Viewing Synthesis Reports
2.3.1. Running Synthesis x
2.3.1.1. Preserving Registers During Synthesis 2.3.1.2. Preserving Signals for Monitoring and Debugging
2.4. Design Place and Route x
2.4.1. Running the Fitter 2.4.2. Viewing Fitter Reports
2.4.1. Running the Fitter x
2.4.1.1. Fitter Commands 2.4.1.2. Disabling or Enabling Physical Synthesis Optimization
2.4.2. Viewing Fitter Reports x
2.4.2.1. Plan Stage Reports 2.4.2.2. Place Stage Reports 2.4.2.3. Route Stage Reports 2.4.2.4. Retime Stage Reports 2.4.2.5. Finalize Stage Reports
2.4.2.2. Place Stage Reports x
2.4.2.2.1. Global Signal Visualization Report
2.4.2.3. Route Stage Reports x
2.4.2.3.1. Global Router Wire Utilization Map Report
2.5. Incremental Optimization Flow x
2.5.1. Concurrent Analysis During Synthesis or Fitting 2.5.2. Analyzing Compiler Snapshots 2.5.3. Validating Periphery (I/O) after the Plan Stage
2.5.2. Analyzing Compiler Snapshots x
2.5.2.1. Running Snapshot Viewer
2.5.2.1. Running Snapshot Viewer x
2.5.2.1.1. Analyzing Failing Paths with Snapshot Viewer 2.5.2.1.2. Analyzing Clocking with Snapshot Viewer 2.5.2.1.3. Analyzing High Fan-out Nets with Snapshot Viewer 2.5.2.1.4. Validating Timing Constraints with Snapshot Viewer 2.5.2.1.5. Analyzing Congestion with Snapshot Viewer
2.6. Fast Forward Compilation Flow x
2.6.1. Step 1: Run Register Retiming 2.6.2. Step 2: Review Retiming Results 2.6.3. Step 3: Run Fast Forward Compile 2.6.4. Step 4: Review Fast Forward Results 2.6.5. Step 5: Implement Fast Forward Recommendations 2.6.6. Retiming Restrictions and Workarounds
2.6.2. Step 2: Review Retiming Results x
2.6.2.1. Locate Critical Chains
2.6.3. Step 3: Run Fast Forward Compile x
2.6.3.1. Fast Forward Compile By Hierarchy 2.6.3.2. HyperFlex Settings
2.6.4. Step 4: Review Fast Forward Results x
2.6.4.1. Clock Fmax Summary Report 2.6.4.2. Fast Forward Details Report
2.8. Exporting Compilation Results x
2.8.1. Exporting a Version-Compatible Compilation Database 2.8.2. Importing a Version-Compatible Compilation Database 2.8.3. Creating a Design Partition 2.8.4. Exporting a Design Partition 2.8.5. Reusing a Design Partition 2.8.6. Viewing Quartus Database File Information 2.8.7. Clearing Compilation Results
2.8.6. Viewing Quartus Database File Information x
2.8.6.1. QDB File Attribute Types
2.9. Integrating Other EDA Tools x
2.9.1. Generating a VQM Netlist for other EDA Tools
2.10. Synthesis Language Support x
2.10.1. Verilog and SystemVerilog Synthesis Support 2.10.2. VHDL Synthesis Support
2.10.1. Verilog and SystemVerilog Synthesis Support x
2.10.1.1. Verilog HDL Input Settings (Settings Dialog Box) 2.10.1.2. Design Libraries 2.10.1.3. Verilog HDL Configuration 2.10.1.4. Initial Constructs and Memory System Tasks 2.10.1.5. Verilog HDL Macros
2.10.1.3. Verilog HDL Configuration x
2.10.1.3.1. Hierarchical Design Configurations
2.10.2. VHDL Synthesis Support x
2.10.2.1. VHDL Input Settings (Settings Dialog Box) 2.10.2.2. VHDL Standard Libraries and Packages 2.10.2.3. VHDL wait Constructs 2.10.2.4. VHDL-2019 Conditional Analysis Tool Directives
2.11. Compiler Optimization Techniques x
2.11.1. Compiler Optimization Modes 2.11.2. Allow Register Retiming 2.11.3. Automatic Gated Clock Conversion 2.11.4. Enable Intermediate Fitter Snapshots 2.11.5. Fast Preserve Option 2.11.6. Fractal Synthesis Optimization
2.11.6. Fractal Synthesis Optimization x
2.11.6.1. Enabling or Disabling Fractal Synthesis
2.12. Synthesis Settings Reference x
2.12.1. Advanced Synthesis Settings
3. Reducing Compilation Time x
3.1. Factors Affecting Compilation Results 3.2. Strategies to Reduce the Overall Compilation Time 3.3. Reducing Synthesis Time and Synthesis Netlist Optimization Time 3.4. Reducing Placement Time 3.5. Reducing Routing Time 3.6. Reducing Static Timing Analysis Time 3.7. Setting Process Priority 3.8. Reducing Compilation Time Revision History
3.2. Strategies to Reduce the Overall Compilation Time x
3.2.1. Running the ECO Compilation Flow 3.2.2. Enabling Multi-Processor Compilation 3.2.3. Using Block-Based Compilation
3.3. Reducing Synthesis Time and Synthesis Netlist Optimization Time x
3.3.1. Settings to Reduce Synthesis Time and Synthesis Netlist Optimization Time 3.3.2. Use Appropriate Coding Style to Reduce Synthesis Time
3.4. Reducing Placement Time x
3.4.1. Placement Effort Multiplier Settings
3.5. Reducing Routing Time x
3.5.1. Identifying Routing Congestion with the Chip Planner
3.5.1. Identifying Routing Congestion with the Chip Planner x
3.5.1.1. Areas with Routing Congestion 3.5.1.2. Congestion due to HDL Coding style
1. Answers to Top FAQs
2. Design Compilation
3. Reducing Compilation Time
4. Intel® Quartus® Prime Pro Edition User Guide Design Compilation Archives
A. Intel® Quartus® Prime Pro Edition User Guides

2.11.3. Automatic Gated Clock Conversion

Clock gating saves power in ASIC designs by adding more logic to a circuit to prune the clock tree. Pruning the clock tree disables portions of the circuitry so that the flip-flops are not required to switch states. When using an Intel® Quartus® Prime FPGA to prototype ASIC designs, you must convert clock gates to clock enables in your design.
Gated Clock Conversion Example
ASIC Gated Clock Example FPGA Clock Enable Example 
module infer_enable (clk, reset, d, en, q);

input d, en, clk, reset;
output q;

wire gated_clk;
reg q;

assign gated_clk = clk & en;
always@(posedge gated_clk or reset)
 begin
               if (!reset) 
                      q <= 1’b0;
              else 
                      q <= d ;
              end 
endmodule
 
module infer_enable (clk, reset, d, en, q);

input d, en, clk, reset;
output q;

reg q;

always@(posedge clk or reset)
 begin
               if (!reset) 
                     q <= 1’b0;
              else if (en)
                     q <= d;
              else 
                      q <= q ;
              end 
endmodule

Rather than manually converting gated clocks in your RTL, you can specify the Auto Gated Clock Conversion setting to automatically convert gated base clocks in the design to clock enables. You can apply this setting globally to all gated base clocks in the design, or to one or more specific clock signals.

Table 24.  Gated Clock Conversion Settings

Setting Scope

Description
Global Enable the Auto Gated Clock Conversion option at Assignments > Settings > Compiler Settings > Advanced Settings (Synthesis). Alternatively, add the global assignment to the project .qsf:
set_global_assignment –name SYNTH_GATED_CLOCK_CONVERSION on
Instance-specific Specify the Auto Gated Clock Conversion for one or more instances in the Assignment Editor (Assignments > Assignment Editor). Alternatively, add the instance assignment to the project .qsf:
set_instance_assignment –name SYNTH_GATED_CLOCK_CONVERSION on –to clk_in
Following design synthesis, view the results of gated clock conversion in the Gated Clock Conversion Details report. The report lists all converted and unconverted gated clocks with their base clocks. For unconverted gated clocks, the report specifies the reason the clock is not converted.
Note: Automatic gated clock conversion supports explicit RAMs (such as WYSIWYG RAMs and Intel FPGA memory IP), but does not support inferred RAMs.
Figure 59.  Gated Clock Conversion Details Report
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