Understanding PMC Reset Sources in Nvidia Jetson Orin Nano Dev Board

Issue Overview

Users of the Nvidia Jetson Orin Nano Dev Board are experiencing confusion regarding the PMC (Power Management Controller) reset sources, specifically the VMON and VREFRO_POWERBAD signals. The issue arises during attempts to conduct power brownout tests on custom carrier boards designed for the Orin Nano. Users are seeking clarification on whether these reset sources are indicative of power-related issues, particularly in the context of system brownouts. The symptoms include uncertainty about the reset causes related to power failures, leading to concerns about the reliability of their setups.

The problem is frequently encountered during testing phases, particularly when users are trying to ensure that their systems can handle power fluctuations without failure. Users have reported inconsistent responses from the board when subjected to brownout conditions, which raises questions about the effectiveness of their designs and configurations.

Possible Causes

1. Hardware Incompatibilities or Defects: Custom carrier boards may not be fully compatible with the Orin Nano module, leading to unexpected behavior during power tests.
2. Software Bugs or Conflicts: Issues within the firmware or JetPack software could prevent accurate reporting of reset causes.
3. Configuration Errors: Incorrect setup of the PMC settings or misconfiguration of the carrier board could lead to misunderstandings about reset sources.
4. Driver Issues: Outdated or incompatible drivers may not properly handle power management features, resulting in erroneous behavior.
5. Environmental Factors: External conditions such as inadequate power supply or overheating could affect performance and reporting.
6. User Errors or Misconfigurations: Improper wiring or settings during testing may lead to misleading results regarding reset causes.

Troubleshooting Steps, Solutions & Fixes

1. Verify Hardware Setup:

   • Ensure that all connections are secure and correctly configured according to Nvidia’s specifications for the Orin Nano.
   • Use only officially supported carrier boards to avoid compatibility issues.

2. Check Software Versions:

   • Confirm that you are using a stable version of JetPack (preferably JetPack 5.x) rather than developer previews which may have unresolved issues.
   • Use the command:

     dpkg -l | grep nvidia
     

     to check installed driver versions.

3. Monitor Serial Console Logs:

   • After triggering a reset (software or hardware), observe the serial console logs during boot-up for any messages related to reset causes.
   • Use commands like:

     dmesg | grep reset
     

     to filter relevant log entries.

4. Conduct Power Brownout Tests:

   • Implement controlled power tests by gradually reducing power supply while monitoring system responses.
   • Document any occurrences of resets and correlate them with specific VMON and VREFRO_POWERBAD readings if available.

5. Update Drivers and Firmware:

   • Regularly check for updates to drivers and firmware that may address known issues with power management.
   • Use SDK Manager for firmware updates, ensuring your board is in recovery mode if necessary.

6. Consult Documentation:

   • Look for any official Nvidia documentation that details PMC reset sources and their implications on system behavior.
   • Engage with community forums for shared experiences and solutions from other users facing similar issues.

7. Testing with Different Configurations:

   • If possible, test with different hardware configurations (e.g., alternate carrier boards) to isolate whether the issue is specific to a particular setup.

8. Best Practices for Future Prevention:

   • Implement robust power supply designs that include capacitors or other components to mitigate brownout effects.
   • Regularly review and update configurations based on community feedback and Nvidia’s guidelines.

By following these steps, users can better diagnose and potentially resolve issues related to PMC reset sources on their Nvidia Jetson Orin Nano Dev Boards, ensuring more reliable operation under varying power conditions.