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Altera_Forum's avatar
Altera_Forum
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21 years ago

DMA transfert inside interrupt routine

Hi, with a NIOSII and uCosII system, I'm trying to implement a DMA memory to memory transfert inside a interrupt routine (as described below). However the DMA transfert never finishs,...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
21 years ago

Yes, all interrupts are disabled (by default) when you are in an interrupt routine. You can reenable higher priority interrupts but it isn't usually a good idea.

The usual way to do this would be to start the DMA transfer from one interrupt and finish it from another interrupt (the DMA completion routine).

So if you aren&#39;t able to acknowledge the interrupt before you have transferred the data then you have two options: a) redesign the hardware so that you are able to acknowledge the interrupt before you have transferred the data or http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/cool.gif disable the interrupt from your interrupt routine and reenable it from the DMA completion function (which, as you know, runs from the DMA controllers interrupt routine).