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Altera_Forum's avatar
Altera_Forum
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14 years ago

DMA Transfer problem

Hi, I am trying to do a simple DMA mem to mem transfer as per the "Chap24: DMA controller core " example. I have been at this for almost a week now and it is still not working for me. Can you p...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

After you write the control register I would expect the status register bits [1:0] to be non-zero (either busy transferring or done). As a result you have while (!(non_zero_value == 0)); .... or in other words an infinite loop. You should mask the busy bit and keep looping until it is set:

while ( ((IORD_ALTERA_AVALON_DMA_STATUS(DMA_0_BASE) & ALTERA_AVALON_DMA_STATUS_DONE_MSK) != ALTERA_AVALON_DMA_STATUS_DONE_MSK ) {

// spin

}

If that software change still doesn't work run it in the simulation since it'll be easier to debug with the driver out of the way.