Code

SAM D20 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC4_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_TC0_EVU

#define CONF_TC_MODULE TC4

SAM D21 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC4_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_DMAC_CH_0

#define CONF_TC_MODULE TC4

SAM R21 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC4_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_DMAC_CH_0

#define CONF_TC_MODULE TC4

SAM D11 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC2_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_DMAC_CH_0

#define CONF_TC_MODULE TC2

SAM L21 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC4_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_DMAC_CH_0

#define CONF_TC_MODULE TC4

SAM L22 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC0_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_DMAC_CH_0

#define CONF_TC_MODULE TC0

SAM DA1 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC4_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_DMAC_CH_0

#define CONF_TC_MODULE TC4

SAM C21 Xplained Pro

#define CONF_EVENT_GENERATOR    EVSYS_ID_GEN_TC4_OVF
#define CONF_EVENT_USER         EVSYS_ID_USER_DMAC_CH_0

#define CONF_TC_MODULE TC4

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

static volatile uint32_t event_count = 0;

void event_counter(struct events_resource *resource);

static void configure_event_channel(struct events_resource *resource)
{
    struct events_config config;

    events_get_config_defaults(&config);

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

    events_allocate(resource, &config);
}

static void configure_event_user(struct events_resource *resource)
{
    events_attach_user(resource, CONF_EVENT_USER);
}

static void configure_tc(struct tc_module *tc_instance)
{
    struct tc_config config_tc;
    struct tc_events config_events;

    tc_get_config_defaults(&config_tc);

    config_tc.counter_size    = TC_COUNTER_SIZE_8BIT;
    config_tc.wave_generation = TC_WAVE_GENERATION_NORMAL_FREQ;
    config_tc.clock_source    = GCLK_GENERATOR_1;
    config_tc.clock_prescaler = TC_CLOCK_PRESCALER_DIV64;

    tc_init(tc_instance, CONF_TC_MODULE, &config_tc);

    config_events.generate_event_on_overflow = true;
    tc_enable_events(tc_instance, &config_events);

    tc_enable(tc_instance);

}

static void configure_event_interrupt(struct events_resource *resource,
        struct events_hook *hook)
{
    events_create_hook(hook, event_counter);

    events_add_hook(resource, hook);
    events_enable_interrupt_source(resource, EVENTS_INTERRUPT_DETECT);
}


void event_counter(struct events_resource *resource)
{
    if(events_is_interrupt_set(resource, EVENTS_INTERRUPT_DETECT)) {
        port_pin_toggle_output_level(LED_0_PIN);

        event_count++;
        events_ack_interrupt(resource, EVENTS_INTERRUPT_DETECT);

    }
}

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

struct tc_module       tc_instance;
struct events_resource example_event;
struct events_hook     hook;

system_init();
system_interrupt_enable_global();

configure_event_channel(&example_event);
configure_event_user(&example_event);
configure_event_interrupt(&example_event, &hook);
configure_tc(&tc_instance);