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Altera_Forum's avatar
Altera_Forum
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20 years ago

How does NiosII communicate with other FPGA blocks

Hi,

I am designing a simple CPU+FPGA application. The FPGA has data bus

for setting registers, one at a time. The data bus includes

inputs: TSData[15:0]

Addr [3:0]

TSDataRdy

TSControl

TSControlValid

output: TCdata[15:0]

TCDataRdy

TCControlRdyToAccpet

So, in SOPC, what's the best way to set up the CPU external interface

for talking to FPGA? Should I use PIO or some exsiting memory controller?

Thanks a lot,

6 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    Hi,

    I think you can use user interface logic.

    You can write the proper timing logic between avalon and user interface and add to the SOPC.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    Hi,

    Maybe a simple question.

    How can I make avalon bus available to custom logic module?

    Should I choose a component from SOPC builder? Which one?

    Thanks!
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    As I know you need not to add any component called Avalon bus since SOPC Builder by default does all the connections to cpu thru Avalon. You know what all signals you need to connect to Avalon signals. Make an HDL entity where you interface Avalon signals with ur user logic. And add the HDL file of this interface as a new component in SOPC Builder. Read "Avalon Bus Specification" for details on what all signals you require for interfacing with Avalon.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    Use component editor (PIO is too simple for most external interfacing). If your interface uses non-Avalon timing add some extra logic to conform to the standard (see the Avalon Bus Spec). If your interface goes off chip and runs at a significantly high speed I recommend re-syncronizing the signals with registers.