int main(void) {
if (PM->RCAUSE.reg & (PM_RCAUSE_POR | PM_RCAUSE_BOD12 | PM_RCAUSE_BOD33)) {
// On powerup, force a clean reset of the MT7620
pin_low(PIN_SOC_RST);
pin_out(PIN_SOC_RST);
// turn off 3.3V to SoC
pin_low(PIN_SOC_PWR);
pin_out(PIN_SOC_PWR);
// pull 1.8V low
pin_low(PIN_18_V);
pin_out(PIN_18_V);
clock_init_crystal(GCLK_SYSTEM, GCLK_32K);
timer_clock_enable(TC_BOOT);
// hold everything low
boot_delay_ms(50); // power off for 50ms
pin_high(PIN_SOC_PWR);
boot_delay_ms(2); // 2ms until 1.8 rail comes on
pin_high(PIN_18_V);
boot_delay_ms(50); // 50ms before soc rst comes on
} else {
clock_init_crystal(GCLK_SYSTEM, GCLK_32K);
}
pin_mux(PIN_USB_DM);
pin_mux(PIN_USB_DP);
usb_init();
usb_attach();
NVIC_SetPriority(USB_IRQn, 0xff);
pin_high(PIN_LED);
pin_out(PIN_LED);
pin_in(PIN_SOC_RST);
pin_high(PIN_SOC_PWR);
pin_out(PIN_SOC_PWR);
pin_low(PORT_A.power);
pin_out(PORT_A.power);
pin_low(PORT_B.power);
pin_out(PORT_B.power);
pin_pull_up(PIN_BRIDGE_CS);
pin_pull_up(PIN_FLASH_CS);
pin_pull_up(PIN_SERIAL_TX);
pin_pull_up(PIN_SERIAL_RX);
dma_init();
NVIC_EnableIRQ(DMAC_IRQn);
NVIC_SetPriority(DMAC_IRQn, 0xff);
eic_init();
NVIC_EnableIRQ(EIC_IRQn);
NVIC_SetPriority(EIC_IRQn, 0xff);
evsys_init();
NVIC_EnableIRQ(EVSYS_IRQn);
NVIC_SetPriority(EVSYS_IRQn, 0);
adc_init(GCLK_SYSTEM, ADC_REFCTRL_REFSEL_INTVCC1);
dac_init(GCLK_32K);
bridge_init();
port_init(&port_a, 1, &PORT_A, GCLK_PORT_A,
TCC_PORT_A, DMA_PORT_A_TX, DMA_PORT_A_RX);
port_init(&port_b, 2, &PORT_B, GCLK_PORT_B,
TCC_PORT_B, DMA_PORT_B_TX, DMA_PORT_B_RX);
__enable_irq();
SCB->SCR |= SCB_SCR_SLEEPONEXIT_Msk;
init_systick();
while (1) { __WFI(); }
}
/* Timer 0 Initialization */
void timer_init(void)
{
struct tc_config conf_tc;
struct tc_events conf_tc_events = {.generate_event_on_compare_channel[0] = 1};
tc_get_config_defaults(&conf_tc);
conf_tc.clock_source = GCLK_GENERATOR_0;
conf_tc.wave_generation = TC_WAVE_GENERATION_MATCH_FREQ;
conf_tc.counter_16_bit.compare_capture_channel[0] = 0xFFFF;
tc_init(&tc_inst, TC0, &conf_tc);
tc_enable_events(&tc_inst, &conf_tc_events);
tc_enable(&tc_inst);
tc_stop_counter(&tc_inst);
/* Enable TC0 match/capture channel 0 interrupt */
TC0->COUNT16.INTENSET.bit.MC0 = 1;
/* Enable TC0 module interrupt */
NVIC_EnableIRQ(TC0_IRQn);
}
/* DAC Initialization */
void dac_initialize(void)
{
struct dac_config conf_dac;
struct dac_events conf_dac_events = {.on_event_start_conversion = 1};
dac_get_config_defaults(&conf_dac);
conf_dac.clock_source = GCLK_GENERATOR_3;
conf_dac.reference = DAC_REFERENCE_INT1V;
dac_init(&dac_inst, DAC, &conf_dac);
dac_enable_events(&dac_inst, &conf_dac_events);
dac_enable(&dac_inst);
}
/* Event System Initialization */
void evsys_init(void)
{
struct events_resource conf_event_resource;
struct events_config conf_event;
events_get_config_defaults(&conf_event);
conf_event.edge_detect = EVENTS_EDGE_DETECT_NONE;
conf_event.path = EVENTS_PATH_ASYNCHRONOUS;
conf_event.generator = EVSYS_ID_GEN_TC0_MCX_0;
events_allocate(&conf_event_resource, &conf_event);
events_attach_user(&conf_event_resource, EVSYS_ID_USER_DAC_START);
}
/* Initialize the selected waveform buffer with output data */
void buffer_init(void)
{
#if WAVE_MODE==SINE_WAVE
for (i = 0; i < DEGREES_PER_CYCLE; i++) {
sine_wave_buf[i] = (uint16_t)(500 + (500*sin((double)i*DEGREE)));
}
#elif WAVE_MODE==SAW_TOOTH_WAVE
for (i = 0; i < 256; i++) {
sawtooth_wave_buf[i] = i*4;
}
#elif WAVE_MODE==TRIANGLE_WAVE
for (i = 0; i < 128; i++) {
triangle_wave_buf[i] = i*8;
}
for (i = 128; i < 256; i++) {
triangle_wave_buf[i] = 1023 - (i*8);
}
#endif
}
/* Main function */
int main(void)
{
system_init();
timer_init();
dac_initialize();
evsys_init();
buffer_init();
/* Set the TC0 compare value corresponding to specified frequency */
#if WAVE_MODE==SINE_WAVE
tc_set_compare_value(&tc_inst, 0, \
system_gclk_gen_get_hz(GCLK_GENERATOR_0)/(FREQUENCY*360));
#else
tc_set_compare_value(&tc_inst, 0, \
system_gclk_gen_get_hz(GCLK_GENERATOR_0)/(FREQUENCY*256));
#endif
/* Start TC0 timer */
tc_start_counter(&tc_inst);
/* Enable global interrupt */
system_interrupt_enable_global();
while (true) {
}
}
