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Altera_Forum's avatar
Altera_Forum
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18 years ago

Differences between Atlantic and Avalon Streaming Protocols

This is what I noticed from playing between version 6.0sp1 and version

6.1. Seems like to prepare for better integration with SOPC builder,

starting from version 6.1, all the DSP IP blocks started adopted

Avalon streaming interface.

The differences between the two interfaces (that I know of) are briefly highlighted below:

- Only master source and slave sink are supported in Avalon ST. In

Atlantic, master/slave source and master/slave sink are all supported.

- In Avalon ST interface, there can be some latencies before the valid

signal goes high (depends on the individual core).

While the interfaces are drastically different, so far I have not had

much trouble migrating to Avalon ST interface. Signal ports generally

still match up.

Hope this helps!

6 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    I don't fully agree with you on the difference below.

    - Only master source and slave sink are supported in Avalon ST. In

    Atlantic, master/slave source and master/slave sink are all supported.

    The reason is it depends on the core. Avalon ST doesn't explicitly specify if the source/sink is master/slave and it's not necessary. The master/slave is implied by the way the core is designed.

    For example, Altera FIR compiler serves as slave sink and master source which is consistent with your comment.

    However, Altera FFT MegaCore serves as master sink and master source which is not consistent.
  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    Thanks for the update BadtzMaru! I thought I had Avalon ST figured out... =) I will go back and re-read the protocol another day.

    However, at the mean time, out of curisity, do you know whether Altera has a documentation of some sort documenting which core has what kind of slave/master sink/source configuration? I think that would be helpful to everyone like me who's trying to learn about the Altera DSP solutions.
  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    --- Quote Start ---

    I don't fully agree with you on the difference below.

    - Only master source and slave sink are supported in Avalon ST. In

    Atlantic, master/slave source and master/slave sink are all supported.

    The reason is it depends on the core. Avalon ST doesn't explicitly specify if the source/sink is master/slave and it's not necessary. The master/slave is implied by the way the core is designed.

    For example, Altera FIR compiler serves as slave sink and master source which is consistent with your comment.

    However, Altera FFT MegaCore serves as master sink and master source which is not consistent.

    --- Quote End ---

    OT: How do I get rid of the streaming interface on the FIR core? My design was working fine using the old interface and I'd prefer not to switch (actually, I tried to switch, but I couldn't get it to work as well with the streaming interface).
  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    Bland Guy,

    Unfortunately you can't switch back to old interface once you upgrade to 6.1 or after.

    It seemed to me Altera has been pushing all IPs to use Avalon Streaming/MM interface.

    :(
  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    --- Quote Start ---

    Bland Guy,

    Unfortunately you can't switch back to old interface once you upgrade to 6.1 or after.

    It seemed to me Altera has been pushing all IPs to use Avalon Streaming/MM interface.

    :(

    --- Quote End ---

    That's true, the interfaces are totally upgrade and all my IPs have been regenerated.