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Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
9 years ago

Nios II Uart with DMA

In my Nios II system I want to use Uart with DMA. Are there some tutorials or example projects about this topic. I'm using Quartus 13.0. Thanks.
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
9 years ago

It doesn't really make sense to use DMA with a UART. A DMA engine doesn't have a mechanism to stop sending and wait for characters to go out, or wait for input characters to be present before transferring data. The FIFO in a standard UART is so small that the time taken to set up a DMA transfer would be greater than the time to fill the FIFO with a sofware loop.

  • praveenkumar's avatar
    praveenkumar
    Icon for Occasional Contributor rankOccasional Contributor
    5 years ago
    are u saying we cant use dma with uart
  • praveenkumar's avatar
    praveenkumar
    Icon for Occasional Contributor rankOccasional Contributor
    5 years ago

    can u help me receiving 24 bytes with uart @2mbps speed.

    i tried but it was receiving like first byte at last and last byte at first like that.

    how can i overcome this problem