PCIe Interface of Jetson Orin Nano

Issue Overview

Users are experiencing difficulties with the PCIe interface on the Nvidia Jetson Orin Nano Dev board, specifically regarding the ability to connect multiple modules (such as WiFi and Bluetooth) using a single PCIe card. The main symptoms reported include confusion about lane configuration and the limitations of the PCIe interface on the Jetson side.

The issue arises during the planning phase for custom carrier board designs, where users intend to utilize an x4 lane PCIe slot. They seek guidance on whether they can split these lanes to accommodate multiple devices connected via x1 lanes.

The context of this problem is primarily during hardware setup and configuration. Users are looking for documentation or guidelines related to the PCIe interface functionality, which has not been adequately addressed in the available resources. The problem appears to be consistently encountered by multiple users, indicating a common misunderstanding or limitation regarding PCIe lane usage on this platform.

Possible Causes

• Hardware Limitations: The Jetson Orin Nano does not support splitting PCIe lanes directly; instead, it requires a PCIe switch for connecting multiple devices.

• Configuration Errors: Users may not fully understand how to configure their custom carrier boards to work with the Jetson’s PCIe capabilities.

• Documentation Gaps: Lack of clear documentation regarding the PCIe interface and its limitations can lead to misconfigurations and assumptions about functionality.

Troubleshooting Steps, Solutions & Fixes

1. Understanding Lane Configuration:

   • Review the Jetson Orin Nano’s technical specifications to understand the PCIe lane architecture.
   • Confirm that using a PCIe switch is necessary for connecting multiple devices.

2. Gathering System Information:

   • Use the following command to check current PCIe configurations:

     lspci
     

   • This command will list all connected PCIe devices and their configurations.

3. Testing with Different Configurations:

   • If you are attempting to connect multiple devices, consider testing with a single device first to ensure basic functionality.
   • Utilize a PCIe switch for connecting multiple devices if required.

4. Consulting Documentation:

   • Refer to Nvidia’s official documentation regarding the Jetson Orin Nano’s PCIe interface for detailed guidelines.
   • Look for application notes or design guides that specifically address custom carrier board designs.

5. Recommended Approach:

   • Based on user feedback, using a PCIe switch is strongly recommended when connecting multiple modules. This approach has been noted as successful among users in similar situations.

6. Best Practices:

   • Ensure that your power supply meets the requirements for all connected devices.
   • Keep firmware and drivers updated to avoid compatibility issues.

7. Further Investigation:

   • If issues persist after following these steps, consider reaching out to Nvidia support or community forums for advanced troubleshooting assistance.

By following these structured steps, users can effectively diagnose and resolve issues related to the PCIe interface on the Jetson Orin Nano Dev board while ensuring proper configuration for their custom applications.