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Altera_Forum's avatar
Altera_Forum
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17 years ago

accelerating DSP blocks

I have some DSP blocks developped with DSP Builder including Avalon MM blocks to interfacing with the rest of the system.

They work fine but only by sending and receiving data using IOWR and IORD functions.

I've tried to connect with DMA controller using sys/alt_dma functions but it doesn't works yet.

Have you tried to include a DSP block in SOPC builder as custom instruction instead of a DSP builder system?

In this case Do I need to remove the avalon portsin DSP builder?

I'm a little confused, I need set a DMA because execution is too slow using NIOS to feed data.

1 Reply

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

    I believe custom instructions have its own interface: a, b, c, read_a, read_b, write_c, ... etc... I haven't tried this out myself personally, but if you want to use your DSP Builder component as custom instructions in Nios II, then I believe you would have to:

    1. remove the Avalon MM interface blocks

    2. add in the correct CI interfaces (a, b, c, ... etc.)

    3. somehow import that into Nios II... this is the part that I am unsure about.... theoretically, you simply need to import the VHDL or Verilog file to component editor and make sure all ports are set to CI interfaces... however, not sure how this would work with DSPB generated components (since the component is separated into multiple VHDL files....) there is a chance that you might need to file a service request with Altera to see whether it would work or not...

    Best of luck!