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Questions about DMA for external ADC/DAC

Question asked by MarcZ on Apr 30, 2013
Latest reply on May 14, 2013 by MaheshN

Hi,

 

Currently, we are interfacing an external ADC/DAC with AMI.

It works perfectly but makes the DSP "dead" for the amounts of time of reading and writing.

At this point, we have a End of Conversion signal coming from an external ADC which interrupt, and so read, do some calcul and write to an DAC.

 

We have done some experiments with the DMA and it looks like it can work on his own without using much of the core.

Related to this, I have some questions:

 

- Does DMA can start its own transfers, triggered by an external signal (End of Conversion of the ADC)? If this can be done, the End of Conversion could be driven to the DMA itself and have the DMA do the transfer without the processor having to deal with it.

 

- Does DMA can be setup to do multiple, separate (disparate) DMA things? I read something about "chaining" but it is not very clear to me. Does that means that I could setup the DMA to do one batch of transfers, and then automatically do another batch of transfers, then I could setup the DMA to read the A/D into memory, and then write from memory to the DAC, again, instead of having the processor prime its data registers.

 

Thank your you suggestions,

Marc

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