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Altera_Forum
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16 years ago

Avalon Video Streaming Protocol: Control Data packets

Hello,

it seems that I understand something wrong about the representation of imagewidth, imageheigth and interlace-properties in the control data packets and would appreciate another opinion about it.

For example I have a TPG with 800x480, no interlacing, 4:4:4 RGB and 3 color planes in sequence, each color plane represented in 8 bit. How should the control data packet look like? I thought it should look like

0F 30 02 10 0E 03

on the dout bus, but I observe

0F 00 03 02 02 02

with signal tap.

Thanks for reading and best regards

Andreas

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    800 = 0320h

    480 = 01E0h

    Only one nibble (4 bits) of the control information is encoded per word.

    So the width would be sent as the four nibbles 0, 3, 2, 0. The height would be 0, 1, E, 0.

    So looking at the 8 bit data values, I would expect something like: 0F 00 03 02 00 00 01 0E 03
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Thanks for your reply, I overread that there is only one nibble in each 8 bit symbol. (and also some other things :D)

    I guess between 0E and 03 in the code format you posted should be 00.

    regards

    Andreas
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Yes, I did miss a 00 between 0E and 03.

    It's amazing sometimes how easy it is to miss a mistake like that even though I know I double checked it before posting...
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    I also logged some wrong valid and ready signals. Now everything seems to be fine with the format.

    regards

    Andreas