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FPGAOLOG's avatar
FPGAOLOG
Icon for Occasional Contributor rankOccasional Contributor
4 years ago
Solved

Is waitrequestAllowance suported for Altera EMIF external mem interface?

The Avalon document mentions waitrequestAllowance parameter but I cant see a way to set it in either Avalon mm bridge or EMIF Avalon interfaces. How can I set it to 1 for EMIF Avalon interface?
  • FPGAOLOG's avatar
    FPGAOLOG
    4 years ago

    " waitrequest will usually only be ...". There is no usually in RTL. There is always. So waitrequest may be asserted DURING the burst. This means everything connected to waitrequest must be combinatorial, and can't be pipelined.

    Thanks for the help. You may close this ticket.

sstrell's avatar
sstrell
Icon for Super Contributor rankSuper Contributor
4 years ago

If you're using Platform Designer, you don't really have a choice in the matter. waitrequest is a required signal for the Avalon standard and required by PD on the host side.

If you are instantiating the EMIF directly in your Quartus project, it does not need to have the Avalon wrapper.

Did you try creating an example design from the EMIF parameter editor to see what this type of connection between user logic and the controller can look like?