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Altera_Forum's avatar
Altera_Forum
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20 years ago

DMA transfer from SDRAM to PIO

Hello.

I'm now trying to use DMA for transferring data from SDRAM to PIO.

But I don't know how to use DMA in eCos.

(I searched this forum, but I couldn't find.)

Can someone teach me how to use DMA ?

If possible, could you show me a simple example.

(I'm newbe for embedded system.

For me, This is first time to use DMA.)

Thank you.

Best regards.

2 Replies

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

    To simplify life, I wouldn&#39;t use any eCos DMA stuff; I&#39;d talk right to the DMA hardware with IORD/IOWR (in <cyg/hal/io.h>). Read the Altera documentation on the DMA peripheral and its registers. Starting the DMA should amount to four IOWR()s; one each to set source and destination addresses and word count, and another to set the transfer-type flags and start the DMA.

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

    Thank you Mike.

    Now, I can use DMA with IOWR.

    And I use your FIFO interface now.

    Thank you again.