Device Design Guidelines: Agilex™ 5 FPGAs and SoCs

ID 813741
Date 4/01/2024
Public
Document Table of Contents

5.3.1.1. Unused Pins

Table 37.  Unused Pins Checklist

Number

Done?

Checklist item

1

 

Specify the reserved state for unused I/O pins.

2

 
Carefully check the pin connections in the Quartus® Prime software-generated .pin file.
Note: Do not connect RESERVED pins.
You can specify the state of unused pins in the Quartus® Prime software to allow flexibility in the board design by choosing one of the five allowable states for Reserve all unused pins on the Unused Pins category in the Device and Pin Options dialog box:
  • As inputs tri-stated
  • As output driving ground
  • As outputs driving an unspecified signal
  • As input tri-stated with bus-hold circuitry
  • As input tri-stated with weak pull-up
The following list describes some of the settings and their purpose:
  • The common setting is to set unused pins As inputs tri-stated with weak pull-up.
  • To improve signal integrity, set the unused pins to As output driving ground. Doing this reduces inductance by creating a shorter return path and reduces noise on the neighboring I/Os.
    Note: Do not use this approach if this results in many paths causing congestion for signals under the device.
  • To reduce power dissipation, set clock pins and other unused I/O pins As inputs tri-stated and tie them to GND.

Connection Guidelines for Unused HPS Block

If you are not using the HPS block in the Agilex™ 5 SoC device, you can follow the guidelines below for HPS specific pins:

Table 38.  HPS Supply Pins

Pin Function

If HPS is unused, connect to:

VCCL_HPS

VCCL_HPS_CORE0_CORE1 1

VCCL_HPS_CORE21

VCCL_HPS_CORE31

VCCIO_HPS

VCCPLL1_HPS

VCCPLL2_HPS

VCCPLLDIG1_HPS

VCCPLLDIG2_HPS

If you do not intend to utilize the HPS in the Agilex™ 5 SoC device, you must still provide power to the HPS power supplies.

For more information, refer to the Pin Connection Guidelines: Agilex™ 5 FPGAs and SoCs .

48 HPS Dedicated IO

No connect (NC)

1 Can be tied to GND if unused.