How to access DDR4 RAM of TX2 for storing RAW video data directly, without CSI Interface.

Hi Nvidia,

I want to access the DDR4 RAM externally, As TX2 has 400pins, Any pins can give direct access to DDR4 RAM?
To store the captured RAW video data bypassing the CSI interface.

1 Like

What’s your usecase? From PCIE interface is an possible way.

Hi Shane,

Thanks for the quick reply,
a) I am desiging TX2 carrier board along with FPGA kintex 7.
b) I am using FPGA for 12G SDI & HDMI 2.0 input conversion to CSI.
c) Input video 4K 60fps/30fps (4:2:0)

FPGA will get the input from HDMI & 12G SDI input (4k RAW video frames) and write it to external DDR3 RAM(of FPGA),
then CSI (of FPGA) will read video frame from external DDR3 RAM and pass it to CSI Interface of TX2 Board.

  1. I want to avoid extra writing and Reading as mentioned above and make FPGA to pass 4K RAW video frames
    from HDMI & SDI Inputs(of FPGA) to LPDDR4 memory of TX2.

  2. so that i can completly avoid CSI module both in FPGA & TX2.

Questions :

  1. With PCI what is the max data rate supported ? i am looking for 4K capture from HDMI & SDI both simultaniously?
    4K 60fps/30fps (4:2:0)

  2. The MIPI CSI connector of TX2 can be used to connect to FMC connector of FPGA through any of the convertor cables?

  1. Reference to below link to find the speed. Don’t understand the second question.

Hi Shane,

Thanks for reply , I have few more quires regarding the PCI

  1. If my input is “RBG format” from SDI/HDMI and if I directly write to DDR4 RAM using PCI → DMA… ,
    How to convert RBG to YUV 4:2:0 ? ISP will come in to Picture?

  2. With PCI approach , The capturing examples works ?
    a) tegra_multimedia_api/samples/12_camera_v4l2_cuda ?
    b) tegra_multimedia_api/samples/10_camera_recording ?


  1. ISP not support this pipeline yet you may need some software to do it.
  2. Not working. However you can implement your own v4l2 driver to capture the data.

Hi meRaza,
Did you successfully getting 4K@60fps HDMI input? I am very excited about this problem.
Best regards.