Intel® Quartus® Prime Standard Edition User Guide: Design Constraints

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ID 683492
Date 1/10/2019
Public
Document Table of Contents
Document Table of Contents x
1. Constraining Designs 2. Managing Device I/O Pins A. Intel® Quartus® Prime Standard Edition User Guides
1. Constraining Designs x
1.1. Specifying Design Constraints Designs in the GUI 1.2. Constraining Designs with Tcl Scripts 1.3. A Fully Iterative Scripted Flow 1.4. Constraining Designs Revision History
1.1. Specifying Design Constraints Designs in the GUI x
1.1.1. Global Constraints and Assignments 1.1.2. Node, Entity, and Instance-Level Constraints 1.1.3. Probing Between Components of the Intel® Quartus® Prime GUI 1.1.4. Specifying Timing Constraints in the GUI
1.1.2. Node, Entity, and Instance-Level Constraints x
1.1.2.1. Specify Instance-Specific Constraints in Assignment Editor 1.1.2.2. Specify I/O Constraints in Pin Planner 1.1.2.3. Adjust Constraints with the Chip Planner 1.1.2.4. Constraining Designs with the Design Partition Planner
1.2. Constraining Designs with Tcl Scripts x
1.2.1. Create a Project and Apply Constraints 1.2.2. Assigning a Pin 1.2.3. Generating Intel® Quartus® Prime Settings Files 1.2.4. Synopsys* Design Constraint (.sdc) Files 1.2.5. Tcl-only Script Flows
1.2.5. Tcl-only Script Flows x
1.2.5.1. Tcl-only Timing Analysis
2. Managing Device I/O Pins x
2.1. I/O Planning Overview 2.2. Assigning I/O Pins 2.3. Importing and Exporting I/O Pin Assignments 2.4. Validating Pin Assignments 2.5. Verifying I/O Timing 2.6. Viewing Routing and Timing Delays 2.7. Analyzing Simultaneous Switching Noise 2.8. Scripting API 2.9. Managing Device I/O Pins Revision History
2.1. I/O Planning Overview x
2.1.1. Basic I/O Planning Flow 2.1.2. Integrating PCB Design Tools 2.1.3. Intel Device Terms
2.2. Assigning I/O Pins x
2.2.1. Assigning to Exclusive Pin Groups 2.2.2. Assigning Slew Rate and Drive Strength 2.2.3. Assigning Differential Pins 2.2.4. Entering Pin Assignments with Tcl Commands 2.2.5. Entering Pin Assignments in HDL Code
2.2.3. Assigning Differential Pins x
2.2.3.1. Overriding I/O Placement Rules on Differential Pins
2.2.5. Entering Pin Assignments in HDL Code x
2.2.5.1. Using Synthesis Attributes 2.2.5.2. Using Low-Level I/O Primitives
2.3. Importing and Exporting I/O Pin Assignments x
2.3.1. Importing and Exporting for PCB Tools 2.3.2. Migrating Assignments to Another Target Device
2.4. Validating Pin Assignments x
2.4.1. I/O Assignment Validation Rules 2.4.2. Checking I/O Pin Assignments in Real-Time 2.4.3. I/O Assignment Analysis 2.4.4. Understanding I/O Analysis Reports
2.4.3. I/O Assignment Analysis x
2.4.3.1. Early I/O Assignment Analysis Without Design Files 2.4.3.2. I/O Assignment Analysis With Design Files 2.4.3.3. Overriding Default I/O Pin Analysis
2.5. Verifying I/O Timing x
2.5.1. Running Advanced I/O Timing 2.5.2. Adjusting I/O Timing and Power with Capacitive Loading
2.5.1. Running Advanced I/O Timing x
2.5.1.1. Board Trace Models 2.5.1.2. Defining the Board Trace Model 2.5.1.3. Modifying the Board Trace Model 2.5.1.4. Specifying Near-End vs Far-End I/O Timing Analysis 2.5.1.5. Advanced I/O Timing Analysis Reports
2.8. Scripting API x
2.8.1. Generate Mapped Netlist 2.8.2. Reserve Pins 2.8.3. Set Location 2.8.4. Exclusive I/O Group 2.8.5. Slew Rate and Current Strength
1. Constraining Designs
2. Managing Device I/O Pins
A. Intel® Quartus® Prime Standard Edition User Guides

2.4.3.2. I/O Assignment Analysis With Design Files

I/O assignment analysis allows you to perform full I/O legality checks after fully defining HDL design files. When you run I/O assignment analysis on a complete design, the tool verifies all I/O pin assignments against all I/O rules. When you run I/O assignment analysis on a partial design, the tool checks legality only for defined portions of the design. The following figure shows the work flow for analyzing pin-outs with design files.

Figure 10. I/O Assignment Analysis Flow

Even if I/O assignment analysis passes on incomplete design files, you may still encounter errors during full compilation. For example, you can assign a clock to a user I/O pin instead of assigning to a dedicated clock pin, or design the clock to drive a PLL that you have not yet instantiated in the design. This issues occur because I/O assignment analysis does not account for the logic that the pin drives and does not verify that only dedicated clock inputs can drive the a PLL clock port.

To obtain better coverage, analyze as much of the design as possible over time, especially logic that connects to pins. For example, if your design includes PLLs or LVDS blocks, define these files prior to full analysis. After performing I/O assignment analysis, correct any errors reported by the Fitter and rerun I/O assignment analysis until all errors are corrected.

The following figure shows the compilation time benefit of performing I/O assignment analysis before running a full compilation.

Figure 11. I/O Assignment Analysis Reduces Compilation Time
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