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Altera_Forum's avatar
Altera_Forum
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13 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";