Intel® Quartus® Prime Pro Edition User Guide: Timing Analyzer

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ID 683243
Date 10/04/2021
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Document Table of Contents
Document Table of Contents x
1. Timing Analysis Introduction 2. Using the Intel® Quartus® Prime Timing Analyzer A. Intel® Quartus® Prime Pro Edition User Guides
1. Timing Analysis Introduction x
1.1. Timing Analysis Basic Concepts 1.2. Timing Analysis Overview Document Revision History
1.1. Timing Analysis Basic Concepts x
1.1.1. Timing Path and Clock Analysis 1.1.2. Clock Setup Analysis 1.1.3. Clock Hold Analysis 1.1.4. Recovery and Removal Analysis 1.1.5. Multicycle Path Analysis 1.1.6. Metastability Analysis 1.1.7. Timing Pessimism 1.1.8. Clock-As-Data Analysis 1.1.9. Multicorner Timing Analysis 1.1.10. Time Borrowing
1.1.1. Timing Path and Clock Analysis x
1.1.1.1. The Timing Netlist 1.1.1.2. Timing Paths 1.1.1.3. Data and Clock Arrival Times 1.1.1.4. Launch and Latch Edges
1.1.5. Multicycle Path Analysis x
1.1.5.1. Multicycle Clock Hold 1.1.5.2. Multicycle Clock Setup
1.1.10. Time Borrowing x
1.1.10.1. Time Borrowing Limitations 1.1.10.2. Time Borrowing with Latches
2. Using the Intel® Quartus® Prime Timing Analyzer x
2.1. Timing Analysis Flow 2.2. Step 1: Specify Timing Analyzer Settings 2.3. Step 2: Specify Timing Constraints 2.4. Step 3: Run the Timing Analyzer 2.5. Step 4: Analyze Timing Reports 2.6. Applying Timing Constraints 2.7. Timing Analyzer Tcl Commands 2.8. Timing Analysis of Imported Compilation Results 2.9. Using the Intel® Quartus® Prime Timing Analyzer Document Revision History 2.10. Intel® Quartus® Prime Pro Edition User Guide: Timing Analyzer Archive
2.4. Step 3: Run the Timing Analyzer x
2.4.1. Setting the Operating Conditions 2.4.2. Enabling Time Borrowing Optimization
2.5. Step 4: Analyze Timing Reports x
2.5.1. Generating Timing Reports 2.5.2. Cross-Probing with Design Assistant 2.5.3. Launching Design Assistant from Timing Analyzer 2.5.4. Locating Timing Paths in Other Tools 2.5.5. Correlating Constraints to the Timing Report
2.5.1. Generating Timing Reports x
2.5.1.1. Report Fmax Summary 2.5.1.2. Report Timing 2.5.1.3. Report Data Delay 2.5.1.4. Report Clocks and Clock Networks 2.5.1.5. Report Clock Transfers 2.5.1.6. Report Logic Depth 2.5.1.7. Report Neighbor Paths 2.5.1.8. Report Register Spread 2.5.1.9. Report Route Net of Interest 2.5.1.10. Report Retiming Restrictions 2.5.1.11. Report Reset Statistics 2.5.1.12. Report Pipelining Information 2.5.1.13. Report Asynchronous CDC 2.5.1.14. Report CDC Viewer 2.5.1.15. Report Time Borrowing Data 2.5.1.16. Report Exceptions and Exceptions Reachability
2.5.1.8. Report Register Spread x
2.5.1.8.1. Registers with High Timing Path Endpoint Tension 2.5.1.8.2. Registers with High Immediate Fan-Out Tension
2.5.2. Cross-Probing with Design Assistant x
2.5.2.1. Cross-Probing from Design Assistant to Timing Analyzer
2.6. Applying Timing Constraints x
2.6.1. Recommended Initial SDC Constraints 2.6.2. SDC File Precedence 2.6.3. Modifying Iterative Constraints 2.6.4. Using Entity-bound SDC Files 2.6.5. Creating Clocks and Clock Constraints 2.6.6. Creating I/O Constraints 2.6.7. Creating Delay and Skew Constraints 2.6.8. Creating Timing Exceptions 2.6.9. Using Fitter Overconstraints 2.6.10. Example Circuit and SDC File
2.6.1. Recommended Initial SDC Constraints x
2.6.1.1. Create Clock (create_clock) 2.6.1.2. Derive PLL Clocks (derive_pll_clocks) 2.6.1.3. Derive Clock Uncertainty (derive_clock_uncertainty) 2.6.1.4. Set Clock Groups (set_clock_groups)
2.6.4. Using Entity-bound SDC Files x
2.6.4.1. Entity-bound Constraint Scope 2.6.4.2. Entity-bound Constraint Examples
2.6.5. Creating Clocks and Clock Constraints x
2.6.5.1. Creating Base Clocks 2.6.5.2. Creating Virtual Clocks 2.6.5.3. Creating Generated Clocks (create_generated_clock) 2.6.5.4. Deriving PLL Clocks 2.6.5.5. Creating Clock Groups (set_clock_groups) 2.6.5.6. Accounting for Clock Effect Characteristics 2.6.5.7. Constraining CDC Paths
2.6.5.1. Creating Base Clocks x
2.6.5.1.1. Automatic Clock Detection and Constraint Creation
2.6.5.2. Creating Virtual Clocks x
2.6.5.2.1. Specifying I/O Interface Uncertainty 2.6.5.2.2. I/O Interface Clock Uncertainty Example
2.6.5.3. Creating Generated Clocks (create_generated_clock) x
2.6.5.3.1. Clock Divider Example (-divide_by) 2.6.5.3.2. Clock Multiplexer Example
2.6.5.5. Creating Clock Groups (set_clock_groups) x
2.6.5.5.1. Exclusive Clock Groups (-logically_exclusive or -physically_exclusive) 2.6.5.5.2. Asynchronous Clock Groups (-asynchronous) 2.6.5.5.3. set_clock_groups Constraint Tips
2.6.5.6. Accounting for Clock Effect Characteristics x
2.6.5.6.1. Set Clock Latency (set_clock_latency) 2.6.5.6.2. Clock Uncertainty
2.6.6. Creating I/O Constraints x
2.6.6.1. Input Constraints (set_input_delay) 2.6.6.2. Output Constraints (set_output_delay)
2.6.7. Creating Delay and Skew Constraints x
2.6.7.1. Advanced I/O Timing and Board Trace Model Delay 2.6.7.2. Maximum Skew (set_max_skew) 2.6.7.3. Net Delay (set_net_delay)
2.6.8. Creating Timing Exceptions x
2.6.8.1. Timing Exception Precedence 2.6.8.2. False Paths (set_false_path) 2.6.8.3. Minimum and Maximum Delays 2.6.8.4. Multicycle Paths 2.6.8.5. Multicycle Exception Examples 2.6.8.6. Delay Annotation 2.6.8.7. Constraining Design Partition Ports
2.6.8.4. Multicycle Paths x
2.6.8.4.1. Common Multicycle Applications 2.6.8.4.2. Relaxing Setup with Multicycle (set_multicyle_path) 2.6.8.4.3. Accounting for a Phase Shift (-phase)
2.6.8.5. Multicycle Exception Examples x
2.6.8.5.1. Default Multicycle Analysis 2.6.8.5.2. End Multicycle Setup = 2 and End Multicycle Hold = 0 2.6.8.5.3. End Multicycle Setup = 2 and End Multicycle Hold = 1 2.6.8.5.4. Same Frequency Clocks with Destination Clock Offset 2.6.8.5.5. Destination Clock Frequency is a Multiple of the Source Clock Frequency 2.6.8.5.6. Destination Clock Frequency is a Multiple of the Source Clock Frequency with an Offset 2.6.8.5.7. Source Clock Frequency is a Multiple of the Destination Clock Frequency 2.6.8.5.8. Source Clock Frequency is a Multiple of the Destination Clock Frequency with an Offset
2.7. Timing Analyzer Tcl Commands x
2.7.1. The quartus_sta Executable 2.7.2. Collection Commands
2.7.2. Collection Commands x
2.7.2.1. Wildcard Characters 2.7.2.2. Adding and Removing Collection Items 2.7.2.3. Query of Collections 2.7.2.4. Using the get_pins Command
1. Timing Analysis Introduction
2. Using the Intel® Quartus® Prime Timing Analyzer
A. Intel® Quartus® Prime Pro Edition User Guides

2.2. Step 1: Specify Timing Analyzer Settings

Before running timing analysis, you must open an Intel® Quartus® Prime project and run the Fitter to generate the timing netlist. You can consider and specify general settings for timing analysis, as well as other project-wide Compiler settings that impact the timing analysis results:
To specify general Timing Analyzer settings, follow these steps:
  1. Click File > New Project Wizard to create a new project, or click File > Open Project to open an existing project.
  2. Click Assignments > Settings > Timing Analyzer to open the Timing Analyzer settings.
    Figure 37. Timing Analyzer Page (Settings Dialog Box)
  3. In the Timing Analyzer page, specify one or more .sdc file for timing analysis, and any of the following options:
    Table 3.  Timing Analyzer General Settings
    Setting Description
    SDC files to include in the project Specifies the name and processing order of Synopsis Design Constraint (.sdc) files in the project.
    Interactive Timing Analysis Specify options for automatically running timing analysis, reading constraints, and generating reports automatically. Turn on or off:
    • Automatically launch Timing Analyzer GUI after a full compilation (default, on)
    • Automatically read constraints and update the timing netlist when project is opened in Timing Analyzer (default, on)
    • Automatically run setup summary report when project is opened in Timing Analyzer (default, on)
    Default Reporting Specify options to automatically Report worst-case paths during compilation (default, on). Specify the Paths reported per clock domain (default, 10), and whether to Show routing (default, off) in reports.
    Tcl Script Options Tcl Script File name specifies the file name for a custom timing analysis script. You can specify whether to Run default timing analysis before running custom script.
    Metastability Analysis Specifies how the Timing Analyzer identifies registers as being part of a synchronization register chain for metastability analysis.
  4. Consider and specify project-wide Compiler settings that can have a significant impact on Timing Analysis:
    Table 4.  Compiler Settings Impacting Timing Analysis
    Setting Description Location
    Enable multicorner support for Timing Analyzer and EDA Netlist Writer(default, on) Directs the Timing Analyzer to perform multicorner timing analysis by default, which analyzes the design against best-case and worst-case operating conditions. Assignments > Settings > Compilation Process Settings
    Optimization Mode (default, Balanced) Specifies the focus of Compiler optimization efforts during synthesis and fitting. Specify a Balanced strategy, or optimize for Performance, Area, Power, Routability, or Compile Time. Assignments > Settings > Compiler Settings
    SDC Constraint Protection (default, off)

    Verifies.sdc constraints in register merging. This option helps to maintain the validity of .sdc constraints through compilation.

    		Assignments > Settings > Compiler Settings > Advanced Settings (Synthesis)
    Synchronization Register Chain Length (default, 3)

    Specifies the maximum number of registers in a row that the Compiler considers as a synchronization chain. The Compiler considers these registers for metastability analysis. The Compiler prevents optimizations of these registers, such as retiming. When gate-level retiming is enabled, the Compiler does not remove these registers.

    		Assignments > Settings > Compiler Settings > Advanced Settings (Synthesis)
    Optimize Design for Metastability (default, on)

    This setting improves the reliability of the design by increasing its Mean Time Between Failures (MTBF). The Fitter increases the output setup slacks of synchronizer registers in the design. This slack can exponentially increase the design MTBF. This option only applies when using the Timing Analyzer for timing-driven compilation. Use the Timing Analyzer report_metastability command to review the synchronizers detected in your design and to produce MTBF estimates.

    		Assignments > Settings > Compiler Settings > Advanced Settings (Fitter)
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