Valid Camera Input configurations on Jetson AGX Xavier

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
1

This question is about the combination of CSI-2 cameras that can be connected to the Xavier AGX. The Xavier AGX SOM has 6 camera processors and a total of 16 CSI D-PHY lanes. Is the following configuration supported:

Three 4-lane cameras (12 lanes total) and three 1-lane cameras (3 lanes total).

This fits within the 16 lanes available on the SOM, but may not work based on how the lanes must be connected to the SOM. Referring to Table 50 (CSI Configurations, D-PHY Mode) of the Jetson Xavier OEM Product Design Guide, if I connect one 4-lane camera to CSI 2&3, another 4-lane camera to CSI 4&5, and a third 4-lane camera to CSI 6&7, that leaves CSI 0 and 1 (4 lanes total) for the three 1-lane cameras. The design guide says I can place a 1-lane camera where each 2-lane camera is shown (shaded in green), but can I split a 2-lane bundle into two 1-lane interfaces? The total camera count would be 6, which is the limit, but can the lanes be assigned as I show? Or would I be limited to only two 1-lane cameras?

I think I cannot do it because the clock for each CSI interface is for both lanes of each CSI, so I can’t split a 2-lane CSI into 2 separate cameras.

2

@adam
Yes, the clock is the key, so you can’t connect three one lane camera to csi0 - csi3, You only can connect two one lane camera to csi0 and csi2

3

Shane,

Thanks for the reply. I think you are agreeing with me, but I wanted to clarify/correct exactly what you are saying. In my scenario, I’m leaving CSI 0 & 1 (each with 2 lanes) available for 1-lane cameras, so a more comprehensive (and corrected) version of what you are saying would be: (my corrections in bolded orange)

“Yes, the clock is the key, so you can’t connect three one lane cameras to csi0 - csi1, You only can connect two one lane cameras to csi0 and csi1”

4

Below link should be more clear for the CSI port binding.

https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fcamera_sensor_prog.html%23wwpID0E0J10HA

5

Dear CSI expert,

I plan to interface a 4-lane imager to Jetson AGX Xavier using CSI0_D0_P/N, CSI0_D1_P/N, CSI1_D0_P/N CSI1_D1_P/N and CSI0_CLK_P/N. Is there any example of the port-binding in the devicetree, please ?

Thanks in advance,