PCB Design Guidelines: Agilex™ 3 FPGAs and SoCs

ID 853726
Date 8/20/2025
Public
Document Table of Contents

6.1.1. FPGA DDR Break Out Routing

Agilex™ 3 devices come with various pitch sizes for different FPGA pins. For VPBGA package devices breakout, Altera recommends you use a dog bone configuration, stripline routing for inner GPIO pins fan out and microstrip routing for GPIO pins at edge of the device.

DQS and CLK signals in the DDR interface are differential signals. Altera recommends routing the DQS/CLK signal as differential signals and use a symmetrical fan-out at the FPGA pin field.

Figure 30. Symmetrical Routing of Differential Signals (DQS/CLK) at FPGA Pin FieldThis figure shows the symmetrical routing of differential signals (DQS/CLK) at FPGA pin field and the length/skew matching between P and N lanes.