25.8.7.1.2 Code

Add to the main application source file, before any functions, according to the kit used:

SAM D21 Xplained Pro.

#define CONF_PWM_MODULE      LED_0_PWM4CTRL_MODULE

#define CONF_PWM_CHANNEL     LED_0_PWM4CTRL_CHANNEL

#define CONF_PWM_OUTPUT      LED_0_PWM4CTRL_OUTPUT

#define CONF_PWM_OUT_PIN     LED_0_PWM4CTRL_PIN

#define CONF_PWM_OUT_MUX     LED_0_PWM4CTRL_MUX

#define CONF_TCC_CAPTURE_CHANNEL      1

#define CONF_TCC_EVENT_GENERATOR      EVSYS_ID_GEN_TCC0_MCX_0

#define CONF_TCC_EVENT_USER           EVSYS_ID_USER_TCC0_MC_1

#define CONF_COMPARE_TRIGGER TCC0_DMAC_ID_OVF

#define CONF_CAPTURE_TRIGGER TCC0_DMAC_ID_MC_1

SAM R21 Xplained Pro.

#define CONF_PWM_MODULE      LED_0_PWM4CTRL_MODULE

#define CONF_PWM_CHANNEL     LED_0_PWM4CTRL_CHANNEL

#define CONF_PWM_OUTPUT      LED_0_PWM4CTRL_OUTPUT

#define CONF_PWM_OUT_PIN     LED_0_PWM4CTRL_PIN

#define CONF_PWM_OUT_MUX     LED_0_PWM4CTRL_MUX

#define CONF_TCC_CAPTURE_CHANNEL      1

#define CONF_TCC_EVENT_GENERATOR      EVSYS_ID_GEN_TCC0_MCX_3

#define CONF_TCC_EVENT_USER           EVSYS_ID_USER_TCC0_MC_1

#define CONF_COMPARE_TRIGGER TCC0_DMAC_ID_OVF

#define CONF_CAPTURE_TRIGGER TCC0_DMAC_ID_MC_1

SAM L21 Xplained Pro.

#define CONF_PWM_MODULE      LED_0_PWM4CTRL_MODULE

#define CONF_PWM_CHANNEL     LED_0_PWM4CTRL_CHANNEL

#define CONF_PWM_OUTPUT      LED_0_PWM4CTRL_OUTPUT

#define CONF_PWM_OUT_PIN     LED_0_PWM4CTRL_PIN

#define CONF_PWM_OUT_MUX     LED_0_PWM4CTRL_MUX

#define CONF_TCC_CAPTURE_CHANNEL      1

#define CONF_TCC_EVENT_GENERATOR      EVSYS_ID_GEN_TCC0_MCX_0

#define CONF_TCC_EVENT_USER           EVSYS_ID_USER_TCC0_MC_1

#define CONF_COMPARE_TRIGGER TCC0_DMAC_ID_OVF

SAM L22 Xplained Pro.

#define CONF_PWM_MODULE      LED_0_PWM4CTRL_MODULE

#define CONF_PWM_CHANNEL     LED_0_PWM4CTRL_CHANNEL

#define CONF_PWM_OUTPUT      LED_0_PWM4CTRL_OUTPUT

#define CONF_PWM_OUT_PIN     LED_0_PWM4CTRL_PIN

#define CONF_PWM_OUT_MUX     LED_0_PWM4CTRL_MUX

#define CONF_TCC_CAPTURE_CHANNEL      1

#define CONF_TCC_EVENT_GENERATOR      EVSYS_ID_GEN_TCC0_MCX_0

#define CONF_TCC_EVENT_USER           EVSYS_ID_USER_TCC0_MC_1

#define CONF_COMPARE_TRIGGER TCC0_DMAC_ID_OVF

SAM DA1 Xplained Pro.

#define CONF_PWM_MODULE      LED_0_PWM4CTRL_MODULE

#define CONF_PWM_CHANNEL     LED_0_PWM4CTRL_CHANNEL

#define CONF_PWM_OUTPUT      LED_0_PWM4CTRL_OUTPUT

#define CONF_PWM_OUT_PIN     LED_0_PWM4CTRL_PIN

#define CONF_PWM_OUT_MUX     LED_0_PWM4CTRL_MUX

#define CONF_TCC_CAPTURE_CHANNEL      1

#define CONF_TCC_EVENT_GENERATOR      EVSYS_ID_GEN_TCC0_MCX_0

#define CONF_TCC_EVENT_USER           EVSYS_ID_USER_TCC0_MC_1

#define CONF_COMPARE_TRIGGER TCC0_DMAC_ID_OVF

#define CONF_CAPTURE_TRIGGER TCC0_DMAC_ID_MC_1

SAM C21 Xplained Pro.

#define CONF_PWM_MODULE      LED_0_PWM4CTRL_MODULE

#define CONF_PWM_CHANNEL     LED_0_PWM4CTRL_CHANNEL

#define CONF_PWM_OUTPUT      LED_0_PWM4CTRL_OUTPUT

#define CONF_PWM_OUT_PIN     LED_0_PWM4CTRL_PIN

#define CONF_PWM_OUT_MUX     LED_0_PWM4CTRL_MUX

#define CONF_TCC_CAPTURE_CHANNEL      1

#define CONF_TCC_EVENT_GENERATOR      EVSYS_ID_GEN_TCC0_MCX_0

#define CONF_TCC_EVENT_USER           EVSYS_ID_USER_TCC0_MC_1

#define CONF_COMPARE_TRIGGER TCC0_DMAC_ID_OVF

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

struct tcc_module tcc_instance;

uint16_t capture_values[3] = {0, 0, 0};
struct dma_resource capture_dma_resource;
COMPILER_ALIGNED(16) DmacDescriptor capture_dma_descriptor;
struct events_resource capture_event_resource;

uint16_t compare_values[3] = {
    (0x1000 / 4), (0x1000 * 2 / 4), (0x1000 * 3 / 4)
};
struct dma_resource compare_dma_resource;
COMPILER_ALIGNED(16) DmacDescriptor compare_dma_descriptor;

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

static void config_event_for_capture(void)
{
    struct events_config config;

    events_get_config_defaults(&config);

    config.generator      = CONF_TCC_EVENT_GENERATOR;
    config.edge_detect    = EVENTS_EDGE_DETECT_RISING;
    config.path           = EVENTS_PATH_SYNCHRONOUS;
    config.clock_source   = GCLK_GENERATOR_0;

    events_allocate(&capture_event_resource, &config);

    events_attach_user(&capture_event_resource, CONF_TCC_EVENT_USER);
}

static void config_dma_for_capture(void)
{
    struct dma_resource_config config;

    dma_get_config_defaults(&config);

    config.trigger_action = DMA_TRIGGER_ACTON_BEAT;
    config.peripheral_trigger = CONF_CAPTURE_TRIGGER;

    dma_allocate(&capture_dma_resource, &config);

    struct dma_descriptor_config descriptor_config;

    dma_descriptor_get_config_defaults(&descriptor_config);

    descriptor_config.block_transfer_count = 3;
    descriptor_config.beat_size = DMA_BEAT_SIZE_HWORD;
    descriptor_config.step_selection = DMA_STEPSEL_SRC;
    descriptor_config.src_increment_enable = false;
    descriptor_config.source_address =
            (uint32_t)&CONF_PWM_MODULE->CC[CONF_TCC_CAPTURE_CHANNEL];
    descriptor_config.destination_address =
            (uint32_t)capture_values + sizeof(capture_values);

    dma_descriptor_create(&capture_dma_descriptor, &descriptor_config);

    dma_add_descriptor(&capture_dma_resource, &capture_dma_descriptor);
    dma_add_descriptor(&capture_dma_resource, &capture_dma_descriptor);
    dma_start_transfer_job(&capture_dma_resource);
}

static void config_dma_for_wave(void)
{
    struct dma_resource_config config;
    dma_get_config_defaults(&config);
    config.trigger_action = DMA_TRIGGER_ACTON_BEAT;
    config.peripheral_trigger = CONF_COMPARE_TRIGGER;
    dma_allocate(&compare_dma_resource, &config);

    struct dma_descriptor_config descriptor_config;

    dma_descriptor_get_config_defaults(&descriptor_config);

    descriptor_config.block_transfer_count = 3;
    descriptor_config.beat_size = DMA_BEAT_SIZE_HWORD;
    descriptor_config.dst_increment_enable = false;
    descriptor_config.source_address =
            (uint32_t)compare_values + sizeof(compare_values);
    descriptor_config.destination_address =
            (uint32_t)&CONF_PWM_MODULE->CC[CONF_PWM_CHANNEL];

    dma_descriptor_create(&compare_dma_descriptor, &descriptor_config);

    dma_add_descriptor(&compare_dma_resource, &compare_dma_descriptor);
    dma_add_descriptor(&compare_dma_resource, &compare_dma_descriptor);
    dma_start_transfer_job(&compare_dma_resource);
}

static void configure_tcc(void)
{
    struct tcc_config config_tcc;
    tcc_get_config_defaults(&config_tcc, CONF_PWM_MODULE);

    config_tcc.counter.clock_prescaler = TCC_CLOCK_PRESCALER_DIV1024;
    config_tcc.counter.period = 0x1000;
    config_tcc.compare.channel_function[CONF_TCC_CAPTURE_CHANNEL] =
            TCC_CHANNEL_FUNCTION_CAPTURE;
    config_tcc.compare.wave_generation = TCC_WAVE_GENERATION_SINGLE_SLOPE_PWM;
    config_tcc.compare.wave_polarity[CONF_PWM_CHANNEL] = TCC_WAVE_POLARITY_0;
    config_tcc.compare.match[CONF_PWM_CHANNEL] = compare_values[2];

    config_tcc.pins.enable_wave_out_pin[CONF_PWM_OUTPUT] = true;
    config_tcc.pins.wave_out_pin[CONF_PWM_OUTPUT]        = CONF_PWM_OUT_PIN;
    config_tcc.pins.wave_out_pin_mux[CONF_PWM_OUTPUT]    = CONF_PWM_OUT_MUX;

    tcc_init(&tcc_instance, CONF_PWM_MODULE, &config_tcc);

    struct tcc_events events_tcc = {
        .input_config[0].modify_action = false,
        .input_config[1].modify_action = false,
        .output_config.modify_generation_selection = false,
        .generate_event_on_channel[CONF_PWM_CHANNEL] = true,
        .on_event_perform_channel_action[CONF_TCC_CAPTURE_CHANNEL] = true
    };
    tcc_enable_events(&tcc_instance, &events_tcc);

    config_event_for_capture();

    config_dma_for_capture();
    config_dma_for_wave();

    tcc_enable(&tcc_instance);
}

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

configure_tcc();

SMART ARM-based Microcontrollers

25.8.7.1.2 Code