DAC — 单 DAC 噪声波

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#include "at32f403a_407_board.h"
#include "at32f403a_407_clock.h"

int main(void)
{
  system_clock_config();

  at32_board_init();

  /* turn led2/led3/led4 on */
  at32_led_on(LED2);
  at32_led_on(LED3);
  at32_led_on(LED4);

  /* enable dac/gpioa clock */
  crm_periph_clock_enable(CRM_DAC_PERIPH_CLOCK, TRUE);
  crm_periph_clock_enable(CRM_GPIOA_PERIPH_CLOCK, TRUE);

  /* once the dac is enabled, the corresponding gpio pin is automatically
     connected to the dac converter. in order to avoid parasitic consumption,
     the gpio pin should be configured in analog */
  gpio_init_struct.gpio_pins = GPIO_PINS_4;
  gpio_init_struct.gpio_mode = GPIO_MODE_ANALOG;
  gpio_init_struct.gpio_out_type = GPIO_OUTPUT_PUSH_PULL;
  gpio_init_struct.gpio_pull = GPIO_PULL_NONE;
  gpio_init_struct.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
  gpio_init(GPIOA, &gpio_init_struct);

  /* dac1 configuration */
  dac_trigger_select(DAC1_SELECT, DAC_SOFTWARE_TRIGGER);

  dac_trigger_enable(DAC1_SELECT, TRUE);

  dac_wave_generate(DAC1_SELECT, DAC_WAVE_GENERATE_NOISE);

  dac_mask_amplitude_select(DAC1_SELECT, DAC_LSFR_BITB0_AMPLITUDE_4095);

  dac_output_buffer_enable(DAC1_SELECT, TRUE);

  /* enable dac1: once the dac1 is enabled, pa.04 is
     automatically connected to the dac converter. */
  dac_enable(DAC1_SELECT, TRUE);

  while(1)
  {
    dac_software_trigger_generate(DAC1_SELECT);
    delay_us(1);
  }
}