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frankbarone's avatar
frankbarone
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8 months ago

Agilex 7 emif ip questions

Hello, I downloaded this document from your site, ug-ag-emi-683216-780962.pdf. All my questions refer to this document. In here, on page 78, there is no information about the width of the address...
Memory
sstrell's avatar
sstrell
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8 months ago

The address bus width of the Avalon interface is as wide as needed to access the controller. Page 323-324 of the document you mention (I had to find the document you mention; including links to documents helps in a forum) shows an example of address mapping but it depends on the Address Ordering parameter set when you parameterize the IP.

The interface is standard Avalon so you should just use the Avalon spec: https://www.intel.com/content/www/us/en/docs/programmable/683091/22-3/introduction-to-the-interface-specifications.html

frankbarone's avatar
frankbarone
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8 months ago
Thank you.
I will give you link to the document in future.

Please explain What you mean by “address bus is as long as controller needs” ?
Isn’t the width of the address bus a constant value for the emif controller ?
If not, what does the width of the address bus depend on? Is there an example anywhere?
I am to use emif controller. It did not occur to me to use Avalon user guide. Mentioning it in the user guid would help.
Could also answer my other question about read write request. I am asking again here -
Is there any example of sending read and write request to the memory controller and waveforms for the same? Though it is Avalon interface, how read and write request are sent depends on how memory controller handles them.
Thank you,
Frank
  • sstrell's avatar
    sstrell
    Icon for Super Contributor rankSuper Contributor
    8 months ago

    No, the address bus width may be different depending on the memory capacity and options chosen for the controller as mentioned. I pointed you to one example of what the address bus might look like (pages 323-324).

    Avalon is a known standard with Altera IP so I guess the user guide is assuming you know what it is. Surprisingly, you're right, there is no link to the spec in the EMIF IP user guide.

    The best way to understand how to issue commands to the controller IP is to generate the EMIF example design. You can take the example design and use it as a starting point for your own and then just replace the traffic generator with your own design once you see how it works issuing requests to the IP.