Integration guide (AxelUltra)

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Axel-04.png Applies to Axel Ultra

Introduction

This page provides useful information and resources to system designers in order to integrate Axel Ultra SOM in his/her application quickly. These information complement SoM-independent recommendations provided in the Carrier board design guidelines (SOM) page.

Several topics are covered, ranging from hardware issues to manufacturing aspects.

Hardware

Reference designs

Several schematics are available in order to accelerate the design of carrier board hosting Axel Ultra SOM. Please note that, even if these schematics are derived from tested real-world applications, they are provided "as is" and they might be modified in order to adapt to your specific application.

Following sections provides some additional information helping to understand schematics.

Available schematics:

Axel Ultra mating connectors

Compatible part numbers are FX8C-140P-SVx by Hirose. x depends on selected stacking height. For more details please see Hirose FX8C Series.

Boot sequence

Axel Ultra default boot sequence can be changed by optional external circuitry.

Carrier board design guidelines

This page provides general guidelines about how to implement carrier boards hosting SOM.

In the following sections further hardware guidelines valid for Axel Ultra are introduced. The information provided here complete the Carrier board design guidelines for some specific interfaces.

Interfaces Guidelines

For interfaces not mentioned in this section, refer to the generic guidelines.

PCI Express

PCB

Routed length for PCI Express Differential Pairs Min Typ Max
Differential Impedance [Ohm] - 97 -
Common Mode Impedance [Ohm] - 50 -
Intra pair matching [mils]* - - 4
Max Length [inches]* - - <1 inches
Stub - - 0
Vias on module - - 2
  • * See detailed trace lengths shown in the following table. These numbers are required to compute overall (SoM + carrier board) lengths.
Axel Ultra pin name Individual trace length [mils]
PCIE_TXP 913,9
PCIE_TXN 913,93
PCIE_RXP 840,35
PCIE_RXN 836,28

Software