求助cs32A101SOC中单端ADC采集配置方法

应用芯片内置运放放大，单端信号0.2-1V输入AIN0.请问应该怎么配置ADC寄存器。PGA1增益1，PGA2增益1?
AINP:AIN0, AINN: Vrefp/2.
在例程上改，输入电压没有线性，一会儿高，一会低，请问怎么回事？
// #define FILTER_LOW_LATENCY_ENABLE
#define FILTER_SINC2_ENABLE
// #define FILTER_SINC3_ENABLE

adc_config_t adc_config;
pga_config_t pga_config;
vref_config_t vref_config;

/*****************************************************************************

• [url=home.php?mod=space&uid=2666770]@Brief[/url] 初始化ADC24

• [url=home.php?mod=space&uid=3142012]@param[/url] 无

• [url=home.php?mod=space&uid=1141835]@Return[/url] 无
  ****************************************************************************/
  void csadc24_init(void)
  {
  / Clock enable /
  // __RCU_AHB_CLK_ENABLE(RCU_AHB_PERI_GPIOA);
  __RCU_APB1_CLK_ENABLE(RCU_APB1_PERI_ADADC);
  __RCU_FUNC_ENABLE(LRC2_CLK);
  / adc clock = LRC2(1.024MHz) */
  rcu_adcclk_config(RCU_ADCLK_CFG_LRC2);

  if(rcu_lrc2_stabilization_wait() == ERROR)
  {
  printf("LRC2 not ready\r\n");
  /* Stop here */
  while(1);
  }
  else
  {
  printf("LRC2 ready\r\n");
  }
  // 初始化ADC24
  adc_def_init(ADC1);
  // - Inner-vref must soft start
  adc_vref_soft_start(ADC1);
  // - Config SDADC
  adc_config_struct_init(&adc_config);
  adc_config.abandont_num = ADC_ABANDONT_DATA_4;
  adc_config.average_num = ADC_AVERAGE_NUM_16;
  adc_config.convert_mode = ADC_SINGLE_CONVERT_MODE;
  adc_config.data_rate = ADC_DATARATE_MODE_4;
  adc_config.gain_select = ADC_GAIN_1;
  adc_config.ovrwr_mode = ADC_DATA_OVER_WRITE;
  adc_config.power_mode = ADC_HIGH_POWER_MODE;
  adc_config.rst_num = ADC_RST_CYCLE_2048;
  adc_config.setup_time = ADC_SETUP_TIME_CYCLE_2048;

  adc_init(ADC1, &adc_config);
  // - Config PGA
  pga_config.din_select = PGA_BOTH_PMOS_NMOS;
  pga_config.pga1_enable = ENABLE;
  pga_config.pga_chop = PGA_CHOP_DISABLE;
  pga_config.pga_gain = ADC_PGA_GAIN_1;

  adc_pga_init(&pga_config);
  // - Config VREF
  vref_config.buffer_enable = ENABLE;
  vref_config.driver = ADC_VREF_DRV_MAX_5MA;
  vref_config.ref_select = ADC_REF_SELECT_INNER_2P048V;
  vref_config.vref_enable = ENABLE;

  adc_vref_init(&vref_config);
  // - Filter selected
  adc_digital_filter_select(ADC1, ADC_FILTER_LOW_LATENCY);
  // - trigger config -- software start
  adc_trigger_config(ADC1, ADC_TRIGGER_MODE_SOFT, ADC_TRIGGER_SRC_RTC);
  adc_chop_freq_set(ADC1,ADC_CHOP_DIV_256);
  // - Swicth filter and Inner channel for calibrate.
  // - Get adc convertion value.
  }

static float adc_data_convert_low_latency(uint32_t adc_data)
{
double convt_data = 0;
if(adc_data & 0x800000)
{
adc_data = (~(adc_data & 0xFFFFFF))+1;
adc_data &= 0x00FFFFFF;

convt_data = (double)adc_data * 1.0235074 * 2.048 / 0x7FFFFF;
    // printf("adc_data %x, adc convert value -%fV \r\n", adc_data,convt_data);
    
}
else
{
    adc_data &= 0x00FFFFFF;
    convt_data = (double)adc_data * 1.0235074 * 2.048 / 0x7FFFFF;
    // printf("adc_data %x, adc convert value +%fV \r\n", adc_data,convt_data);
}
return (float)convt_data;

}

static float adc_data_convert_sinc2(uint32_t adc_data)
{
double convt_data = 0;
if(adc_data & 0x800000)
{
adc_data = (~(adc_data & 0xFFFFFF))+1;
adc_data &= 0x00FFFFFF;

convt_data = (double)adc_data * 0.8192 * 2.048 / 0x7FFFFF;
    
}
else
{
    adc_data &= 0x00FFFFFF;
    convt_data = (double)adc_data * 0.8192 * 2.048 / 0x7FFFFF;
}
return (float)convt_data;

}

static float adc_data_convert_sinc3(uint32_t adc_data)
{
double convt_data = 0;
if(adc_data & 0x800000)
{
adc_data = (~(adc_data & 0xFFFFFF))+1;
adc_data &= 0x00FFFFFF;

convt_data = (double)adc_data * 1.0485755 * 2.048 / 0x7FFFFF;
    // printf("adc_data %x, adc convert value -%fV \r\n", adc_data,convt_data);
    
}
else
{
    adc_data &= 0x00FFFFFF;
    convt_data = (double)adc_data * 1.0485755 * 2.048 / 0x7FFFFF;
    // printf("adc_data %x, adc convert value +%fV \r\n", adc_data,convt_data);
}
return (float)convt_data;

}
/*****************************************************************************

• @brief 获取ADC24转换数据
• @param 无
• @return 转换数据float类型
  ****************************************************************************/
  float get_adc_data(void)
  {
  float adc_data = 0.0f;
  #ifdef FILTER_LOW_LATENCY_ENABLE
  / ADC_FILTER_LOW_LATENCY Outer channel P:ADCIN1 N:ADCIN0 */
  printf("ADC_FILTER_LOW_LATENCY Outer channel P:ADCIN1 N:ADCIN0: \r\n");
  adc_channel_config(ADC1, ADC_INPUT_CHANNEL_0, ADC_INPUT_CHANNEL_14);
  adc_conversion_start(ADC1);
  while(!__ADC_FLAG_STATUS_GET(ADC1, ADC_FLAG_DATA_EOCH));
  adc_data = adc_data_convert_low_latency(__ADC_CONV_VALUE_GET(ADC1));
  #endif

#ifdef FILTER_SINC2_ENABLE
/* ADC_FILTER_SINC2 Outer channel P:ADCIN1 N:ADCIN0 */
adc_channel_config(ADC1, ADC_INPUT_CHANNEL_0, ADC_INPUT_CHANNEL_14);
adc_conversion_start(ADC1);
while(!__ADC_FLAG_STATUS_GET(ADC1, ADC_FLAG_DATA_EOCH));
adc_data = adc_data_convert_sinc2(__ADC_CONV_VALUE_GET(ADC1));
#endif

#ifdef FILTER_SINC3_ENABLE
/* ADC_FILTER_SINC3 Outer channel P:ADCIN1 N:ADCIN0 */
adc_channel_config(ADC1, ADC_INPUT_CHANNEL_1, ADC_INPUT_CHANNEL_0);
adc_conversion_start(ADC1);
while(!__ADC_FLAG_STATUS_GET(ADC1, ADC_FLAG_DATA_EOCH));
adc_data = adc_data_convert_sinc3(__ADC_CONV_VALUE_GET(ADC1));
#endif
return adc_data;
}