Code

SAM D21 Xplained Pro.

#define PWM_MODULE      EXT1_PWM_MODULE

#define PWM_OUT_PIN     EXT1_PWM_0_PIN

#define PWM_OUT_MUX     EXT1_PWM_0_MUX

#define M2M_DMAC_TRIGGER_ID TC6_DMAC_ID_MC_0

SAM R21 Xplained Pro.

#define PWM_MODULE      EXT1_PWM_MODULE

#define PWM_OUT_PIN     EXT1_PWM_0_PIN

#define PWM_OUT_MUX     EXT1_PWM_0_MUX

#define M2M_DMAC_TRIGGER_ID TC3_DMAC_ID_MC_0

SAM D11 Xplained Pro.

#define PWM_MODULE      EXT1_PWM_MODULE

#define PWM_OUT_PIN     EXT1_PWM_0_PIN

#define PWM_OUT_MUX     EXT1_PWM_0_MUX

#define M2M_DMAC_TRIGGER_ID TC1_DMAC_ID_MC_0

SAM L21 Xplained Pro.

#define PWM_MODULE      EXT2_PWM_MODULE

#define PWM_OUT_PIN     EXT2_PWM_0_PIN

#define PWM_OUT_MUX     EXT2_PWM_0_MUX

#define M2M_DMAC_TRIGGER_ID TC0_DMAC_ID_MC_0

SAM L22 Xplained Pro.

#define PWM_MODULE      EXT1_PWM_MODULE

#define PWM_OUT_PIN     EXT1_PWM_0_PIN

#define PWM_OUT_MUX     EXT1_PWM_0_MUX

#define M2M_DMAC_TRIGGER_ID TC0_DMAC_ID_MC_0

SAM DA1 Xplained Pro.

#define PWM_MODULE      EXT1_PWM_MODULE

#define PWM_OUT_PIN     EXT1_PWM_0_PIN

#define PWM_OUT_MUX     EXT1_PWM_0_MUX

#define M2M_DMAC_TRIGGER_ID TC6_DMAC_ID_MC_0

SAM C21 Xplained Pro.

#define PWM_MODULE      EXT1_PWM_MODULE

#define PWM_OUT_PIN     EXT1_PWM_0_PIN

#define PWM_OUT_MUX     EXT1_PWM_0_MUX

#define M2M_DMAC_TRIGGER_ID TC0_DMAC_ID_MC_0

Add to the main application source file, outside of any functions:

struct tc_module tc_instance;

struct dma_resource example_resource;

#define TRANSFER_SIZE    (16)

#define TRANSFER_COUNTER (32)

static uint8_t source_memory[TRANSFER_SIZE*TRANSFER_COUNTER];

static uint8_t destination_memory[TRANSFER_SIZE*TRANSFER_COUNTER];

static volatile bool transfer_is_done = false;

COMPILER_ALIGNED(16)
DmacDescriptor example_descriptor;

Copy-paste the following setup code to your user application:

#define TRANSFER_SIZE    (16)

#define TRANSFER_COUNTER (32)

static uint8_t source_memory[TRANSFER_SIZE*TRANSFER_COUNTER];

static uint8_t destination_memory[TRANSFER_SIZE*TRANSFER_COUNTER];

static volatile bool transfer_is_done = false;

COMPILER_ALIGNED(16)
DmacDescriptor example_descriptor;

void configure_tc(void)
{
    struct tc_config config_tc;
    tc_get_config_defaults(&config_tc);

    config_tc.counter_size    = TC_COUNTER_SIZE_16BIT;
    config_tc.wave_generation = TC_WAVE_GENERATION_NORMAL_PWM;
    config_tc.counter_16_bit.compare_capture_channel[0] = (0xFFFF / 4);

    config_tc.pwm_channel[0].enabled = true;
    config_tc.pwm_channel[0].pin_out = PWM_OUT_PIN;
    config_tc.pwm_channel[0].pin_mux = PWM_OUT_MUX;

    tc_init(&tc_instance, PWM_MODULE, &config_tc);

    tc_enable(&tc_instance);
}

void transfer_done(struct dma_resource* const resource )
{
    UNUSED(resource);

    transfer_is_done = true;
}

void configure_dma_resource(struct dma_resource *resource)
{
    struct dma_resource_config config;

    dma_get_config_defaults(&config);
    config.peripheral_trigger = M2M_DMAC_TRIGGER_ID;

    dma_allocate(resource, &config);
}

void setup_dma_descriptor(DmacDescriptor *descriptor)
{
    struct dma_descriptor_config descriptor_config;

    dma_descriptor_get_config_defaults(&descriptor_config);

    descriptor_config.block_transfer_count = TRANSFER_SIZE;
    descriptor_config.source_address = (uint32_t)source_memory + TRANSFER_SIZE;
    descriptor_config.destination_address =
            (uint32_t)destination_memory + TRANSFER_SIZE;

    dma_descriptor_create(descriptor, &descriptor_config);
}

Add to user application initialization (typically the start of main()):

configure_tc();