Quartus® Prime Pro Edition User Guide: Design Constraints

ID 683143
Date 4/01/2024
Document Table of Contents

3.1. I/O Planning Overview

On FPGA design, I/O planning includes creating pin-related assignments and validating them against pin placement guidelines. This process ensures a successful fit in your target device. When you plan and assign I/O pins in the initial stages of your project, you design for compatibility with your target device and PCB characteristics. As a result, your design process goes through fewer iterations, and you develop an accurate PCB layout sooner.

You can plan your I/O pins even before defining design files. Assign expected nodes not yet defined in design files, including interface IP core signals, and then generate a top-level file. The top-level file instantiates the next level of design hierarchy and includes interface port information like memory, high-speed I/O, device configuration, and debugging tools.

Assign design elements, I/O standards, interface IP, and other properties to the device I/O pins by name or by dragging to cells. You can then generate a top-level design file for I/O validation.

Use I/O assignment validation to fully analyze I/O pins against VCCIO, VREF, electromigration (current density), Simultaneous Switching Output (SSO), drive strength, I/O standard, PCI_IO clamp diode, and I/O pin direction compatibility rules.

Quartus® Prime software provides the Pin Planner tool to view, assign, and validate device I/O pin logic and properties. Alternatively, you can enter I/O assignments in a Tcl script, or directly in HDL code.