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Altera_Forum's avatar
Altera_Forum
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17 years ago

Using Megawizard functions vs. instantiating in SOPC Builder

This is a general question:, I was wondering what the differences between using the MegaWizard Plug-in Manager and SOPC builder are. For example, both tools are able to instantiate a FIFO. So far, my understanding is that in SOPC builder they can be more easily integrated with the Nios II processor. Are there any other advantages or disadvantages of doing it one way or the other?

Also, is it "standard" to have almost an entire system built up in SOPC builder?

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    If you want a master in your SOPC Builder system to access something through Avalon and if that something is in the SOPC Builder component library, then try first to use the built-in SOPC Builder component. If you create your own design block or something like a MegaWizard variation (whether a simple megafunction like a FIFO or something like a memory interface MegaCore without using what the MegaCore's user guide calls the "SOPC Builder flow"), you will need a custom component to interface it to masters in your SOPC Builder system. I've known of someone using a custom component to connect Nios to a memory interface MegaCore, but I'd avoid that unless some special capability is necessary that you don't get using the SOPC Builder flow.

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    I typically use SOPC builder as a sub-component within my design and I always only use it with the NIOS processor. For me, SOPC builder holds no value except for NIOS. As Brad says, if you've got a component that needs to integrate with something in your SOPC system, then use the SOPC version of that component rather than the megacore. Obviously this is typically driven by needing to connect it to NIOS for me.

    Jake
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    In terms of speed, is there a difference between having components inside the SOPC system versus outside?

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Generally the answer to your question is no.

    However it depends on the component in question. In SOPC builder, the complexity of your Avalon bus structure will contribute to the fmax of your design. How this may or may not affect the component you're using really depends on the component and how your bus is structured.

    The same issue affects the megawizard generated component. Your surrounding logic complexity may partly determine the fmax of the component.

    For the purpose of decision-making just say the answer is no.

    Jake