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Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

connection between VIP suite and SGDMA (inconsistent data width)

Hi all

My project is to transfer video data to PCIE.

As my first step, I try to use Test Pattern Generator (TPG) as a temporary video data input and connect the output data from TPG to SGDMA via the Avalon Streaming Interface. The SGDMA works in the transfer mode of "stream-to-memory" and its output is connected to a SDRAM controller IP.

My problem is the inconsistent data width between TPG output and SGDMA input.

The parameter settings in TPG are 720-by-480, 10-bits, and YCbCr 4:2:2. (I'm going to use SDI receiver as the interface of real video data input so the data width must be 10-bits)

QSys shows an error message "Error: System.tpg.dout/sgdma_0.in: The source has 10 bits per symbol, while the sink has 8."

Does anyone know how to solve this problem?

Thanks.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    13 years ago

    Make your source video from the TPG be 8 bits.

    When you output to your SDI receiver, connect the 8 bit video from the TPG to the 8 MSBs of the 10 bit SDI interface.

    The low 2 LSBs you can just set to zero.

    like so:

    SDI_video(9 downto 2) <= TPG_vid_out;

    SDI_video(1 downto 0) <= "00";