cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
RingZero
Visitor
Visitor
510 Views
Registered: ‎04-15-2020

Zynq Ultrascale+ MPSoC DP Controller training issues

Jump to solution

Hello everyone

I'm working with the DisplayPort controller inside a Zynq Ultrascale+ MPSoC. I have been able to get a live video output working correctly on a prototyping board with a native DisplayPort connector and a single lane. I started with the DPDMA example, eventually removing the DMA flow and instead using a live native video interface from the PL.

However, when porting the design to the final platform, which instead has a TI USB-C DisplayPort alternate mode output pipeline and up to two lanes, I am experiencing some issues. When I have two lanes enabled, the application continuously reports successful training, followed by an HPD pulse that initiates retraining, never showing anything on the screen.

However, if I pause the application (through the SDK debugging tools), or if I turn off the monitor from its power button, I will eventually get an output (when I turn the monitor back on, or after some period of the application being paused). Unfortunately, the stream seems unstable. The display periodically shuts on and off, with no indication of any activity from the application (no HPD activity).

It appears to behave better with a single lane enabled; the monitor does not continuously send HPD pulses, but the issue with the display remains.

Has such an operation pattern been observed by anyone here? It's difficult for me to debug this issue.

Thanks!

0 Kudos
1 Solution

Accepted Solutions
bpatil
Xilinx Employee
Xilinx Employee
355 Views
Registered: ‎03-07-2018

Hi @RingZero 

Kindly go through following forum post by @florentw 

https://forums.xilinx.com/t5/Video-and-Audio/Ultrascale-Display-Port-over-USB-C-interface/td-p/1109611

https://forums.xilinx.com/t5/Video-and-Audio/DisplayPort-to-USB-C-in-Ultra96-board/td-p/1112448

Regards,
Bhushan

-------------------------------------------------------------------------------------------------------------------------------------------------
Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.
Give Kudos to a post which you think is helpful and reply oriented.
-------------------------------------------------------------------------------------------------------------------------------------------------

View solution in original post

0 Kudos
3 Replies
watari
Teacher
Teacher
500 Views
Registered: ‎06-16-2013

Hi @RingZero 

 

Did you make sure DPCD value ?

What is your target monitor ?

What is your target resolution and vertical frequency ?

Share USB device and structure, if possible.

 

Nobody reply it without detail information.

Because it depends on them.

 

Best regards,

0 Kudos
RingZero
Visitor
Visitor
479 Views
Registered: ‎04-15-2020

The monitor is an Asus VE248 1920x1080 monitor. According to the DPCD it supports up to 2 lanes and HBR (2.7Gbps).

I have tested the application with both 1024x768 at 60Hz and 1280x720 at 60Hz resolutions. Our test pattern generator module doesn't produce front or back porches, only sync signals. These are the exact video modes and pixel clocks:

Both of these modes are at a 60Hz vertical refresh.

1024x768 mode (pixel clock = 1520 MHz/27; 56.296 MHz):

Active: 1024 (H) 768 (V)
Front porch: 0 (H)  0 (V)
Sync width: 160 (H) 24 (V)
Back porch: 0 (H) 0 (V)
Total: 1184 (H) 792 (V)
Sync polarity: 0 (H) 0 (V)

1280x720 mode (pixel clock = 1520 MHz/23; 66.086 MHz):

Active: 1280 (H) 720 (V)
FrontP: 0 (H) 0 (V)
SyncW: 206 (H) 21 (V)
BackP: 0 (H) 0 (V)
Total: 1486 (H) 741 (V)
Polarity: 0 (H) 0 (V)

The USB PD controller is a Texas Instruments TPS65981, and the USB-C high-speed lanes are output through a TUSB1046AI-DCIRNQR alternate mode redriver. The redriver is configured for 4 DisplayPort lanes. An off-the-shelf USB-C hub provides a native DisplayPort output. The hub supports DP alternate mode pin configuration C.

0 Kudos
bpatil
Xilinx Employee
Xilinx Employee
356 Views
Registered: ‎03-07-2018

Hi @RingZero 

Kindly go through following forum post by @florentw 

https://forums.xilinx.com/t5/Video-and-Audio/Ultrascale-Display-Port-over-USB-C-interface/td-p/1109611

https://forums.xilinx.com/t5/Video-and-Audio/DisplayPort-to-USB-C-in-Ultra96-board/td-p/1112448

Regards,
Bhushan

-------------------------------------------------------------------------------------------------------------------------------------------------
Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.
Give Kudos to a post which you think is helpful and reply oriented.
-------------------------------------------------------------------------------------------------------------------------------------------------

View solution in original post

0 Kudos