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How to use Kinetis K66 with eDMA to scan muliti ADC channel?

Question asked by jet li on Nov 1, 2016
Latest reply on Dec 25, 2016 by jet li

         Recently,I try to use Kinetis K66 with eDMA to achieve scan muliti ADC0 with channel 12,13,15,18,19.Each acquisition ADC0 channel 12,13,15,18,18 interval of 200us。The DMA interrupt is triggered every ten times to read the buffered data.

        My configuration is as follows:

①.configure PDB as every 200us to trigger ADC0.

②.configure ADC0 as Hardware trigger.every finish to request DMA transfer;

③.configure eDMA_Channel2,form ADC0_RA to ADC0_BUFF;

④.configure eDMA_Channel1,form ADC0_trigger to ADC0_SC2;    (Theoretically,It can change the ADC trigger mode SW or HW).

⑤.configure eDMA_Channel0,form ADC0_channel to ADC0_SC1A ;(Theoretically, It can change ADC0 next transaction channel );

 

      I know someone in the KL17 to achieve the three-tier DMA to achieve less CPU intervention in the collection, but I can not contact him. But I don‘t know whether K66 can also implement this process;

      my problem is: I can only achieve the two-tier DMA to transfer the data,But three can not,My idea is to achieve DMA channel 2 is transferred connect to DMA channel 1 each time the transfer completes two bytes, DMA channel 1 is transferred connect to DMA channel0 each time the transfer complete one byte.How do I configure DMA TCDs? 

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