Integration guide (Axel)

Info Box Applies to Axel Ultra Applies to Axel Lite

Introduction

This page provides useful information and resources to system designers in order to quickly integrate AXEL SoMs in his/her application. 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.

Additional very specific guidelines are detailed here here for Axel Ultra SOM.

Software reset management

For Axel Lite SOM, please refer to this section.

For Axel Ultra SOM, please refer to this section.

Bootstrap configuration

For Axel Lite SOM, please refer to this section.

For Axel Ultra SOM, please refer to this section.

Manufacture mode management (Dual Lite/Solo-based systems only)

For Axel Lite SOM, please refer to this section.

For Axel Ultra SOM, please refer to this section.

Power management

Default power management scheme may not be suited for the specific application. That's why it is strongly suggested to verify if it is needed to change it. For more details please refer to this page.

Internal routing information

Axel Lite

A spreadsheet is available for download at this link containing detailed information about Axel Lite routing. These information should be used to check nets matching of the overall system (carrier board + SOM).

Real-time clock (RTC)

Axel Lite

To understand how Axel Lite's real-time clock works, first it is necessary to describe how it is powered.

Real-time clock is integrated in iMX6 processor. As such, it belongs to SNVS power domain. This domain, in turn, is powered by PMIC, via PMIC_VSNSV rail (see also this page). PMIC integrates a sort of switch. When 3V3VIN voltage is applied, this is used to power SNVS domain. Otherwise energy is drawn from PMIC_LICELL, if a coin cell battery is connected (for more details please refer to ).

It is worth remembering that 3.0V lithium batteries are supported. When Axel Lite enters RTC mode and 3V3VIN voltage is removed, current absorption from PMIC_LICELL pin is about 135uA. This value is relatively high with respect to the typical lithium coin cell battery capacity (10 - 50mAh) that may not satisfy RTC keep alive time requirement. In this case, please consider the use of an external low-power RTC device.