TMS320F28379D: ADC with DMA for all adc channels

Mark,

As I understand your problem, ADCA/B/C/D all are utilized while operating channels 1,2,5 and 6. The parallelism for these channels will be possible but not for channels 3 and 4.

Since there are 16 SOCs for each ADC, you need not switch the CHSEL register everytime, rather initialize the channels with different numbered SOC. That should eliminate the need to update the SOCxCTL register everytime.

Are you need of operating all the channels in parallel with data being sent to the DMA at the same instant for all channels? If so, you can try reading the data in the ISR only when the last conversion is complete. This will reduce the output frequency but will suffice the need to synchronize the operation.

Thanks,

Aditya

Hello Aditya,

Yes, you got it right. Im using SOC0 - SOC9 for oversample. So I only have to do it in series and gradually switch dma buffers and ADC channels with CHSEL. It would be best if all adc channels work in parallel. I don't know if I will have enough time to process the sampled buffers in series.

Or, can i feed buffers with round robin algorithm only with 2 DMA channels ?
Example: Set DMA Source CH1 for Buffer1, after conversion 1sample CHSEL to another adc channel, and change DMA Source CH1 Buffer3  1 sample and again... Same for DMA CH2 .. But this seems be slower, i need faster method its realtime signal.

- Mark

Thanks for answer. So for DMA CH1 and CH2 ISR I just trigger ADCC at SOC7 ? and for DMA CH3 ADC/A or D ?
Like this ?

static void DMA_CH1_Init(volatile Uint16 *adcRes)
{
    DMACH1ModeConfig(DMA_ADCCINT1, PERINT_ENABLE, ONESHOT_DISABLE,
                     CONT_ENABLE, SYNC_DISABLE, SYNC_SRC,
                     OVRFLOW_DISABLE, SIXTEEN_BIT, CHINT_END,
                     CHINT_ENABLE);
}

static void DMA_CH3_Init(volatile Uint16 *adcRes)
{
    DMACH1ModeConfig(DMA_ADCAINT1, PERINT_ENABLE, ONESHOT_DISABLE, //Trigger Set ADC A
                     CONT_ENABLE, SYNC_DISABLE, SYNC_SRC,
                     OVRFLOW_DISABLE, SIXTEEN_BIT, CHINT_END,
                     CHINT_ENABLE);
}

ADAINTSEL1N2.bit.INT1SEL = 15;
ADBINTSEL1N2.bit.INT1SEL = 7;
ADCINTSEL1N2.bit.INT1SEL = 7;
ADDINTSEL1N2.bit.INT1SEL = 15;

Mark,

This looks good to me. Did you try this on the setup? Were the results in line with expectations?

Thanks,

Aditya

Hi, I did it and it works perfectly for me. Simple and quick solution to the problem, thank you very much for the information.