cc2650: Data transfer from Sensor Controller via DMA

Andrei Abramchuk

Regards, Experts!

For best performance I need to implement data transfer from Sensor Controller to Cortex-M3 memory via DMA channel. I have found one suitable channel: UDMA_CHAN_AUX_SW.
How to handle this task? How to send "AUX Software event" from Sensor Controller? What Interrupt Vector Number for ISR-Handler I should implement when DMA finish one block transfer?

Thanks!
Andrei

over 9 years ago

0 Tom Kopriva over 9 years ago

TI__Mastermind 20480 points

Hi Andrei,

I think a DMA transfer probably possible, but I don't know of an example that does this. Perhaps one of the examples in the Sensor Controller Studio has one that utilizes the DMA controller.

I think you'd want to trigger the software event from the SC that wakes up the MCU domain to perform a DMA transfer. I'm not sure if you can use the AUX_SW uDMA channel or if you want the MCU to generate a software triggered DMA transfer. There might be some trade-offs when you put the MCU in a low power state while keeping the SC running.

Let me see if I can find someone with more knowledge with the SC.

Tom

0 Andrei Abramchuk over 9 years ago in reply to Tom Kopriva

Intellectual 310 points

Hi Tom!
I just tested an app when Sensor Controller configure and start ADC with ADC_TRIGGER_AUX_TIMER0. ADC sampling period is 5us (200kHz).
DMA channel UDMA_CHAN_AUX_ADC configured to PingPong mode at side of Cortex-M3. It works fine! Cortex-M3 is appears in the ISR-Handler (INT_AUX_ADC vector) only for reconfiguration of the PingPong structure.
So, I intend to implement similar behavior via DMA channel UDMA_CHAN_AUX_SW. But unfortunately I did not find enough information in the technical documentation.
Andrei

0 Nick Tompkins over 9 years ago in reply to Andrei Abramchuk

Intellectual 445 points

Where did you find this adc timer 0 example?

0 Andrei Abramchuk over 9 years ago in reply to Nick Tompkins

Intellectual 310 points

It is my own App. For now it is 1ch 200kHz data logger. Target App is 2ch 100kHz design.

0 Nick Tompkins over 9 years ago in reply to Andrei Abramchuk

Intellectual 445 points

Andrei that's great I have been getting some ok results with the GPtimer driver and the raw way of getting the adc to sample without the SCS stuff. I was unaware that you could do timer based sampling within SCS! Is that app example something you are willing to share?

0 Andrei Abramchuk over 9 years ago in reply to Nick Tompkins

Intellectual 310 points

Program for Sensor Controller:

adcEnableSync(ADC_REF_FIXED, ADC_SAMPLE_TIME_2P7_US, ADC_TRIGGER_MANUAL);
adcFlushFifo();
adcEnableSync(ADC_REF_FIXED, ADC_SAMPLE_TIME_2P7_US, ADC_TRIGGER_AUX_TIMER0);

U16 n=0;
adcSelectGpioInput(cfg.pAuxioASensorOutput[n]);
n = 1 - n;

adcStartAuxTimer0Trigger(5);

while (state.exit == 0) {
//    adcSelectGpioInput(cfg.pAuxioASensorOutput[n]);
    n = 1 - n;
}

adcStopAuxTimer0Trigger();
adcDisable();

Program for Cortex-M3:

static void dma_config(void)
{
    /* Config here dmaControlTableEntry and dmaControlTableEntry_Alt for Ping-Pong operation. */
}

static void adc_Isr(UArg arg)
{
    /* Reconfig dmaControlTableEntry or dmaControlTableEntry_Alt for next loop. */
}

static void dma_open(void)
{
    if (!Power_setDependency(PERIPH_UDMA)) while(1);

    /* Select the primary data structures. */
    HWREG(UDMA0_BASE + UDMA_O_CLEARCHNLPRIALT) = (1<<UDMA_CHAN_AUX_ADC);
    /* Set Channel Enable. */
    HWREG(UDMA0_BASE + UDMA_O_SETCHANNELEN) = (1<<UDMA_CHAN_AUX_ADC);

    /* Disable, configure and enable DMA channel. */
    HWREG(AUX_EVCTL_BASE + AUX_EVCTL_O_DMACTL) &= ~(AUX_EVCTL_DMACTL_EN);
    HWREG(AUX_EVCTL_BASE + AUX_EVCTL_O_DMACTL) = (AUX_EVCTL_DMACTL_SEL_FIFO_NOT_EMPTY |
                                                  AUX_EVCTL_DMACTL_REQ_MODE_SINGLE);
    HWREG(AUX_EVCTL_BASE + AUX_EVCTL_O_DMACTL) = (AUX_EVCTL_DMACTL_SEL_FIFO_NOT_EMPTY |
                                                  AUX_EVCTL_DMACTL_REQ_MODE_SINGLE    |
                                                  AUX_EVCTL_DMACTL_EN);
}

static void sc_open(void)
{
    // Initialize the Sensor Controller
    scifOsalInit();
    scifOsalRegisterCtrlReadyCallback(scCtrlReadyCallback);
    scifOsalRegisterTaskAlertCallback(scTaskAlertCallback);
    scifInit(&scifDriverSetup);

    /* Reset Sensor Controller Task. */
    scifResetTaskStructs(BV(SCIF_ADC_DATA_LOGGER_TASK_ID), BV(SCIF_STRUCT_CFG));

    /* Start Sensor Controller Task. */
    scifExecuteTasksOnceNbl(BV(SCIF_ADC_DATA_LOGGER_TASK_ID));
}

void adc_open(void)
{
    Hwi_Params hwiParams;

    Power_setConstraint(Power_SB_DISALLOW);

    // Setup HWI handler
    Hwi_Params_init(&hwiParams);
    Hwi_construct(&hwiStruct, INT_AUX_ADC, adc_Isr, &hwiParams, NULL);

    dma_config();
    dma_open();
    sc_open();
}

0 Andrei Abramchuk over 9 years ago in reply to Tom Kopriva

Intellectual 310 points

Hi Tom!

Do you have any news on my task? Is it possible to transfer data from SC via DMA channel UDMA_CHAN_AUX_SW?

0 pavan kote over 9 years ago in reply to Andrei Abramchuk

Prodigy 25 points

Hi Andrei,
Please can you provide me a Program for Sensor Controller and main.c file of Cortex-M3.

0 Andrei Abramchuk over 9 years ago in reply to pavan kote

Intellectual 310 points

Hi Pavan!

My program is already at e2e: http://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/p/532628/1944175#1944175

This is 1-channel 200kHz case. You just have to expand two functions for your purpose. The first function is dma_config() and the second is adc_Isr(). Then call adc_open() from main.c

Example of dma_config() and adc_Isr() from my own project:

static inline void adc_iter(uint32_t udma_mode)
{
    volatile tDMAControlTable *dmaControlTableEntry;
    uint32_t index = adc_index;
    uint16_t* addr = adc_buff[index];

    adc_index = (++index < ADC_BUFF_NUM) ? index : 0;
    index &= 1;

    /* Setup RX side */
    dmaControlTableEntry = (index ? &dmaAdcControlTableEntry : &dmaAdcControlTableEntry_alt);
    dmaControlTableEntry->ui32Control  = udma_mode | UDMA_SIZE_16 | UDMA_SRC_INC_NONE | UDMA_DST_INC_16 | UDMA_ARB_1;
    dmaControlTableEntry->pvSrcEndAddr = (void *)(AUX_ANAIF_BASE + AUX_ANAIF_O_ADCFIFO);
    dmaControlTableEntry->pvDstEndAddr = (void *)((uint32_t)addr + (ADC_BUFF_LEN << 1) - 1);
    dmaControlTableEntry->ui32Control |= UDMACC26XX_SET_TRANSFER_SIZE(ADC_BUFF_LEN);
}

static void dma_config(void)
{
    adc_index = 0;
    adc_iter(UDMA_MODE_PINGPONG);
    adc_iter(UDMA_MODE_PINGPONG);
}

static void adc_Isr(UArg arg)
{
    /* Determine if the DMA channel has completed (UDMACC26XX_channelDone) */
    if (HWREG(UDMA0_BASE + UDMA_O_REQDONE) & (1<<UDMA_CHAN_AUX_ADC))
    {
        adc_iter(UDMA_MODE_PINGPONG);

        /* clear DMA done interrupt (UDMACC26XX_clearInterrupt) */
        HWREG(UDMA0_BASE + UDMA_O_REQDONE) = (1<<UDMA_CHAN_AUX_ADC);
    }

    // Clear ADC_IRQ flag. Note: Missing driver for this.
    HWREGBITW(AUX_EVCTL_BASE + AUX_EVCTL_O_EVTOMCUFLAGSCLR, AUX_EVCTL_EVTOMCUFLAGSCLR_ADC_IRQ_BITN) = 1;
}

BR!

Andrei

Bluetooth®︎

Bluetooth forum

cc2650: Data transfer from Sensor Controller via DMA