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el_gregus
Visitor II
March 15, 2010
Question

STR912 reading from EMI as soon as DMA enabled.

  • March 15, 2010
  • 2 replies
  • 576 views
Posted on March 15, 2010 at 20:37

STR912 reading from EMI as soon as DMA enabled.

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    2 replies

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    Tomas DRESLER
    Visitor II
    May 17, 2011
    Posted on May 17, 2011 at 10:00

    Probably the external line has got a ''good'' polarity for trigger (I guess ''1''). Try to keep it in different log. value when enabling DMA and report back here!

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    el_gregusAuthor
    Visitor II
    May 17, 2011
    Posted on May 17, 2011 at 10:00

    The problem was solved by changing the flow control.  I was using ''memory to peripheral'' when I should have been using ''peripheral to memory''.  Since the STR912 thought it was transferring FROM memory, it was starting the transfer as soon as the DMA channel was enabled regardless of the state of the external DMA request line.

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