Is it possible to use 2 MIPI DSI Lanes per DSI Port?

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

Hi,

We are using Jetson TX2 and a custom carrier board. We are working on enabling DSI, the documentation is a bit confusing and is basically because there is a different naming convention for port’s name in the module and in the carrier board.

The module as you can see in Figure 12 in [1] has output ports A, B, C and D, each of 2 MIPI DSI Lanes. However, the Display connector on the module has only 2 ports A and B of 4 MIPI DSI Lanes each.

Checking the datasheet for TX2 [2] on page 30, it says that Jetson TX2 can only be used on dual 4 MIPI DSI Lanes (Ports A x4MIPI DSI and Port C x4MIPI DSI) or one big single 8 MIPI DSI port.

In this case, is it correct to assume that if I want to use Port A in 2 MIPI DSI Lane mode (not 4 DSI Lanes) it is not possible? correct? is 4 MIPI DSI Lanes the only way to use it?

-David

[1] JetsonTX1_TX2_Developer_Kit_Carrier_Board_Specification
[2] Jetson_TX2_TX2i_Module_DataSheet_v01

2

Hi, 2 lane mode is supported, please check the DSI chapter in OEM DG. [url]https://developer.nvidia.com/embedded/dlc/jetson-tx2-tx2i-oem-product-designguide[/url]

3

Awesome, thanks for clarifying this.

-David

4

How are you? Mr. David

Our receicer chip from TX2 has only 2 lanes of MIPI DSI Input.
So, I must use Port A in 2 MIPI DSI Lane mode as you mentioned.

You have solved the problem?

If solved, could you share the solution for me?
I am trying until now…

Thanks a lot.
SI J. KIM

5

Hi santa,

There is 2 lane connection example in OEM DG as i mentioned in comment #2, can you tell more detail of your problem on that?

6

Hi David,

Thanks for your fast reply.
When I see the below configuration I can not accept the meaning of correct usage.

[DSI channel configuration]
Dual Link Mode (Up to 8 PHY lanes):
▪ DSI-A (1x4) + DSI-C (1x4) to single display
▪ DSI-A (1x4) to one display, DSI-C (1x4) to a second display
Split Link Mode (Up to 8 PHY lanes):
▪ Two Links with 1-lane each: DSI-A(1x1) + DSI-B (1x1) or DSI-C (1x1) + DSI-D (1x1)
▪ Two Links with 2-lane each: DSI-A(1x2) + DSI-B (1x2) or DSI-C (1x2) + DSI-D (1x2)
▪ Four Links with 1-lane each: DSI-A(1x1) + DSI-B (1x1) + DSI-C (1x1) + DSI-D (1x1)
▪ Four Links with 2-lane each: DSI-A(1x2) + DSI-B (1x2) + DSI-C (1x2) + DSI-D (1x2)

So, I want to get the information on how to use Port A in 2 MIPI DSI Lane.
If possible, I hope to get reference code for configuration.

Thanks.
SI J. KIM

7

Do you mean 2-lane mode on DSI-A for single display? If so, that is supported as figure 28 listed in OEM DG.

8

How are you? Mr. Trumany.

You are right.
Does TX2 support only DSI-A 2 lanes for single display?

Figure 27: DSI Split Link Connections => Four Links with 2-lane each: DSI-A(1x2) + DSI-B (1x2) + DSI-C (1x2) + DSI-D (1x2)

This configuration is right?
When supporting this mode, can I use this mode for 4 display monitors to view seperated 4 videos ?

Thanks.
SI J. KIM

9

Yes for figure 27, 2-lane DSI-A is supported. Only two controllers in Nano, so only two simultaneous displays
are supported.

10

Hi Trumany.

Thanks a lot for your fast reply.
I got your comment.

Thanks.
SI J. KIM