Intel® Quartus® Prime Standard Edition User Guide: PCB Design Tools

ID 683619
Date 9/24/2018
Document Table of Contents Unused Pin Settings

The Unused Pin page specifies the behavior of all unused pins in your design. Use the Unused Pin page to ensure that unused pin settings are compatible with your PCB.

For example, if you reserve all unused pins as outputs driving ground, you must ensure that you do not connect unused I/O pins to VCC pins on your PCB. Connecting unused I/O pins to VCC pins may result in contention that could lead to higher than expected current draw and possible device overstress.

The Reserve all unused pins list shows available unused pin state options for the target device. The default state for each pin is the recommended setting for each device family.

When you reserve a pin as output driving ground, the Fitter connects a ground signal to the output pin internally. You should connect the output pin to the ground plane on your PCB, although you are not required to do so. Connecting the output driving ground to the ground plane is known as creating a virtual ground pin, which helps to minimize simultaneous switching noise (SSN) and ground bounce effects.