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

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ID 683068
Date 2/21/2024
Public
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 Standard Edition User Guides
1. Timing Analysis Introduction x
1.1. Timing Analysis Basic Concepts 1.2. 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 Analysis
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
2. Using the Intel® Quartus® Prime Timing Analyzer x
2.1. Enhanced Timing Analysis for Intel® Arria® 10 Devices 2.2. Basic Timing Analysis Flow 2.3. Using Timing Constraints 2.4. Timing Analyzer Tcl Commands 2.5. Timing Analysis of Imported Compilation Results 2.6. Using the Intel® Quartus® Prime Timing Analyzer Document Revision History
2.2. Basic Timing Analysis Flow x
2.2.1. Step 1: Open a Project and Run the Fitter 2.2.2. Step 2: Specify Timing Constraints 2.2.3. Step 3: Specify General Timing Analyzer Settings 2.2.4. Step 4: Run Timing Analysis 2.2.5. Step 5: Analyze Timing Analysis Results
2.2.5. Step 5: Analyze Timing Analysis Results x
2.2.5.1. Timing Report Commands 2.2.5.2. Set Operating Conditions 2.2.5.3. Fmax Summary Report 2.2.5.4. Report Timing Command 2.2.5.5. Correlating Constraints to the Timing Report 2.2.5.6. Locating Timing Paths in Other Tools
2.3. Using Timing Constraints x
2.3.1. Recommended Initial SDC Constraints 2.3.2. SDC File Precedence 2.3.3. Iterative Constraint Modification 2.3.4. Creating Clocks and Clock Constraints 2.3.5. Creating I/O Constraints 2.3.6. Creating Delay and Skew Constraints 2.3.7. Creating Timing Exceptions 2.3.8. Example Circuit and SDC File
2.3.1. Recommended Initial SDC Constraints x
2.3.1.1. Create Clock (create_clock) 2.3.1.2. Derive PLL Clocks (derive_pll_clocks) 2.3.1.3. Derive Clock Uncertainty (derive_clock_uncertainty) 2.3.1.4. Set Clock Groups (set_clock_groups)
2.3.4. Creating Clocks and Clock Constraints x
2.3.4.1. Creating Base Clocks 2.3.4.2. Creating Virtual Clocks 2.3.4.3. Creating Generated Clocks (create_generated_clock) 2.3.4.4. Deriving PLL Clocks 2.3.4.5. Creating Clock Groups (set_clock_groups) 2.3.4.6. Accounting for Clock Effect Characteristics
2.3.4.1. Creating Base Clocks x
2.3.4.1.1. Automatic Clock Detection and Constraint Creation
2.3.4.2. Creating Virtual Clocks x
2.3.4.2.1. Specifying I/O Interface Uncertainty 2.3.4.2.2. I/O Interface Clock Uncertainty Example
2.3.4.3. Creating Generated Clocks (create_generated_clock) x
2.3.4.3.1. Clock Divider Example (-divide_by) 2.3.4.3.2. Clock Multiplexor Example
2.3.4.5. Creating Clock Groups (set_clock_groups) x
2.3.4.5.1. Exclusive Clock Groups (-exclusive) 2.3.4.5.2. Asynchronous Clock Groups (-asynchronous) 2.3.4.5.3. set_clock_groups Constraint Tips
2.3.4.6. Accounting for Clock Effect Characteristics x
2.3.4.6.1. Set Clock Latency (set_clock_latency) 2.3.4.6.2. Clock Uncertainty
2.3.5. Creating I/O Constraints x
2.3.5.1. Input Constraints (set_input_delay) 2.3.5.2. Output Constraints (set_output_delay)
2.3.6. Creating Delay and Skew Constraints x
2.3.6.1. Advanced I/O Timing and Board Trace Model Delay 2.3.6.2. Maximum Skew (set_max_skew) 2.3.6.3. Net Delay (set_net_delay) 2.3.6.4. Create Timing Netlist
2.3.7. Creating Timing Exceptions x
2.3.7.1. Timing Constraint Precedence 2.3.7.2. False Paths (set_false_path) 2.3.7.3. Minimum and Maximum Delays 2.3.7.4. Multicycle Paths 2.3.7.5. Multicycle Exception Examples 2.3.7.6. Delay Annotation
2.3.7.4. Multicycle Paths x
2.3.7.4.1. Common Multicycle Applications 2.3.7.4.2. Relaxing Setup with Multicycle (set_multicyle_path) 2.3.7.4.3. Accounting for a Phase Shift (-phase)
2.3.7.5. Multicycle Exception Examples x
2.3.7.5.1. Default Multicycle Analysis 2.3.7.5.2. End Multicycle Setup = 2 and End Multicycle Hold = 0 2.3.7.5.3. End Multicycle Setup = 2 and End Multicycle Hold = 1 2.3.7.5.4. Same Frequency Clocks with Destination Clock Offset 2.3.7.5.5. Destination Clock Frequency is a Multiple of the Source Clock Frequency 2.3.7.5.6. Destination Clock Frequency is a Multiple of the Source Clock Frequency with an Offset Multicycle Constraint 2.3.7.5.7. Source Clock Frequency is a Multiple of the Destination Clock Frequency 2.3.7.5.8. Source Clock Frequency is a Multiple of the Destination Clock Frequency with an Offset
2.4. Timing Analyzer Tcl Commands x
2.4.1. The quartus_sta Executable 2.4.2. Collection Commands 2.4.3. Identifying the Intel® Quartus® Prime Software Executable from the SDC File
2.4.2. Collection Commands x
2.4.2.1. Wildcard Characters 2.4.2.2. Adding and Removing Collection Items 2.4.2.3. Query of Collections 2.4.2.4. Using the get_pins Command
1. Timing Analysis Introduction
2. Using the Intel® Quartus® Prime Timing Analyzer
A. Intel® Quartus® Prime Standard Edition User Guides

2.3.7.5.6. Destination Clock Frequency is a Multiple of the Source Clock Frequency with an Offset

This example is a combination of the previous two examples. The destination clock frequency is an integer multiple of the source clock frequency, and the destination clock has a positive phase shift. The destination clock frequency is 5 ns, and the source clock frequency is 10 ns. The destination clock also has a positive offset of 2 ns with respect to the source clock. The destination clock frequency can be an integer multiple of the source clock frequency. The destination clock frequency can be with an offset when a PLL generates both clocks with a phase shift on the destination clock.

The following example shows a design in which the destination clock frequency is a multiple of the source clock frequency with an offset.

Figure 92. Destination Clock is Multiple of Source Clock with Offset

The timing diagram for the default setup check analysis the Timing Analyzer performs.

Figure 93. Setup Timing Diagram
Figure 94. Hold Check Calculation

The setup relationship in this example demonstrates that the data does not require capture at edge one, but rather requires capture at edge two; therefore, you can relax the setup requirement. To adjust the default analysis, you shift the latch edge by one clock period, and specify an end multicycle setup exception of three.

The multicycle exception adjusts the default analysis in this example:

Multicycle Constraint

set_multicycle_path -from [get_clocks clk_src] -to [get_clocks clk_dst] \
     -setup -end 3

The timing diagram for the preferred setup relationship for this example.

Figure 95. Preferred Setup Analysis

The following timing diagram shows the default hold check analysis that the Timing Analyzer performs with an end multicycle setup value of three:

Figure 96. Default Hold Check
Figure 97. Hold Check Calculation

In this example, the hold check one is too restrictive. The data is launched by the edge at 0 ns, and must check against the data that the previous latch edge at 2 ns captures. This event does not occur in hold check one. To adjust the default analysis, you assign end multicycle hold exception of one.

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