Clarification on 4-lane configuration using CSI0_CLK instead of CSI1_CLK on Jetson Orin NX

Robotics & Edge Computing Jetson Systems Jetson Orin NX
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1

Hi,

Following up on the discussion in this thread:
Is it possible to enable 4-lane operation on both CSI connectors of Jetson Orin NX?

I have a few additional questions for clarification.

Just to confirm my understanding —
when you say “CSI0_CLK or CSI2_CLK are supported for x4 configurations, but not CSI1_CLK or CSI3_CLK,”
does this mean that if we change J20’s CSI1_CLK to CSI0_CLK, the 4-lane configuration will work?

Also, to align with the camera’s data lane mapping, we’re considering swapping the data lane order as shown below:

CSI0_D0_N  
CSI0_D0_P  
CSI0_D1_N  
CSI0_D1_P  
CSI0_CLK_N  
CSI0_CLK_P  
CSI1_D0_N  
CSI1_D0_P  
CSI1_D1_N  
CSI1_D1_P

If we connect CSI0_CLK instead of CSI1_CLK and rearrange the data lanes in this order,
would the 4-lane configuration be expected to work properly?

This is quite urgent, so I’d really appreciate your prompt reply.
Thank you.

2

*** Please note that this reply is generated by LLM automatically ***

Based on the provided context, I’ll address the questions and provide a comprehensive answer.

Is it possible to enable 4-lane operation on both CSI connectors of Jetson Orin NX?

According to the Jetson Orin Nano Developer Kit Carrier Board Specification, the CSI connectors support the following configurations:

  • J20: CSI 1 x2 lane
  • J21: CSI 1 x2 lane or 1 x4 lane

This suggests that the Jetson Orin NX DevKit has a similar configuration. However, the provided context does not explicitly confirm this. Nevertheless, assuming the same configuration applies to the Jetson Orin NX, it appears that only one CSI connector (J21) can support 4-lane operation (1 x4 lane).

Does changing the 4-lane configuration work?

The discussion thread mentions that the Boson carrier board from Connect Tech supports 4x2 (connector cam 1-4) or 2x4 (connector cam1 and cam2) configurations. To switch from 4x2 to 2x4, the device tree setting CAM_LANES is changed from 2 to 4. However, JerryChang’s response indicates that Orin NX/Nano has CSI0 D1 and CSI1 D0 P/N always swizzled for P/N, and recommends using the device tree property lane_polarity to configure a polarity swap on any lane.

This implies that simply changing the 4-lane configuration might not work as expected, and additional configuration, such as polarity swapping, might be required.

Will rearranging the data lanes work?

The proposed lane rearrangement is:

  • Instead of: D0, D1, D2, D3
  • Use: D2, D3, D0, D1

JerryChang’s response does not explicitly address this specific lane rearrangement. However, the recommendation to use the lane_polarity property to configure a polarity swap on any lane suggests that the lane arrangement might need to be adjusted to match the camera’s data lane mapping.

In summary, while the Jetson Orin NX might support 4-lane operation on one CSI connector, changing the configuration and rearranging the data lanes might require additional configuration, such as polarity swapping, to work properly. It is recommended to consult the Jetson Orin NX documentation and seek further clarification from the NVIDIA community or support channels for a definitive answer.

Comparison with other topics

The provided context includes several topics related to Jetson Orin NX and camera configurations. Some relevant topics include:

  • “Customized carrier board with two 4-lane ports unable to capture frame properly” (April 18, 2024)
  • “4-Lane MIPI Camera Compatibility with Orin NX” (January 15, 2025)
  • “CSI-2 Lane Swaping” (April 8, 2024)
  • “CSI dual 4lane configuration” (September 12, 2024)

These topics suggest that there are ongoing discussions and challenges related to camera configurations and lane swapping on the Jetson Orin NX platform.

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4

Just to clarify —
is the lane polarity setting something that can be fully handled through software (by modifying the device tree),
or does it also require any hardware-level changes?

Also, aside from adjusting the lane polarity as you mentioned,
are there any other hardware modifications needed to make the 4-lane configuration work properly?

6

hello hyeyum1,

there’s CSI0 and CSI1 lane swaps, and J20 used CSI1 clock.
you may see-also Jetson Orin Nano Developer Kit Carrier Board Reference Design Files,
please check [P3768_A04_Concept_schematics.pdf] for page-18 [CSI CAM CONNECTORS].
as mentioned by the notes, let me re-cap as below..

x4 camera support in current software only works with the lower clock lane of the x4 clock interface.
This means that CSI0_CLK or CSI2_CLK are supported for x4 configurations, but not CSI1_CLK or CSI3_CLK.
Since J20 has CSI1_CLK, only a x2 camera interface is supported.
J21 which uses CSI2_CLK can support both x2 or x4 camera interfaces.

7

Yes, that’s correct.
I’m asking whether the 4-lane configuration will work if we modify the hardware to use CSI0_CLK and also re-arrange the data-lane order as shown below.

CSI0_D0_N  
CSI0_D0_P  
CSI0_D1_N  
CSI0_D1_P  
CSI0_CLK_N  
CSI0_CLK_P  
CSI1_D0_N  
CSI1_D0_P  
CSI1_D1_N  
CSI1_D1_P
8

hello hyeyum1,

yes, 4-lane camera should works per above modification.

10

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