stm32f100c8t6b,ADC-DMA,PA4采样时间过高引发误中断

afeng-366650 提问时间：2012-6-27 08:15 /

当开启PA0外部中断，ADC，DMA传输采样，PA4脚串联电阻拉低，会一直PA0外部中断，PA4脚上的ADC采样时间低于等于7.5周期才不会一直误中断，这难道是BUG吗？

switch (s){
  case Tmp_Samp:
   {
    ADC_Channels = 5;//通道数
    ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
    ADC_InitStructure.ADC_ScanConvMode = ENABLE;//扫描方式
    ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;//单次。连续转换选择
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;//外部中断选择
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;//数据右对齐
    ADC_InitStructure.ADC_NbrOfChannel = ADC_Channels;//指定多少通道转换
    ADC_Init(ADC1, &ADC_InitStructure);
    /* ADC1 regular channels configuration [规则模式通道配置]*/
    ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 2, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 3, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_6, 4, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_7, 5, ADC_SampleTime_55Cycles5);

    ADC1_1 = TRUE;
    ADC1_2 = TRUE;
    ADC1_5 = TRUE;
    ADC1_6 = TRUE;
    ADC1_7 = TRUE;

   break;
   }
  case Pwr_Samp:
   {
    ADC_Channels = 2;//通道数
    ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
   ADC_InitStructure.ADC_ScanConvMode = ENABLE;//扫描方式
   ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;//单次。连续转换选择
   ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;//外部中断选择
   ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;//数据右对齐
   ADC_InitStructure.ADC_NbrOfChannel = ADC_Channels;//指定多少通道转换
   ADC_Init(ADC1, &ADC_InitStructure);
    /* ADC1 regular channels configuration [规则模式通道配置]*/
   ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 1, ADC_SampleTime_239Cycles5);
   ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 2, ADC_SampleTime_7Cycles5);

    ADC1_3 = TRUE;
    ADC1_4 = TRUE;
   //ADC_Channels = 2;//通道数
   break;
   }
  default:
            break;
    }

/* Enable ADC1 DMA */
ADC_DMACmd(ADC1, ENABLE);

/* Enable ADC1 */
ADC_Cmd(ADC1, ENABLE);
/* Enable ADC1 reset calibaration register */
ADC_ResetCalibration(ADC1);
/* Check the end of ADC1 reset calibration register */
while(ADC_GetResetCalibrationStatus(ADC1));
/* Start ADC1 calibaration */
ADC_StartCalibration(ADC1);
/* Check the end of ADC1 calibration */
while(ADC_GetCalibrationStatus(ADC1));

/* Enable DMA1 channel1 */
DMA_Cmd(DMA1_Channel1, ENABLE);

/* Start ADC1 Software Conversion */
ADC_SoftwareStartConvCmd(ADC1, ENABLE);

下面是配置的中断，因PA4下拉引起一直中断
void SW_Init(void)
{
EXTI_InitTypeDef EXTI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

/* Enable ADC1 and GPIOC clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //PA0中断输入
//GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//GPIO_Mode_IPU;//
GPIO_Init(GPIOA, &GPIO_InitStructure);

   /* Enable the RTC Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

/*将EXTI线0连接到PA0*/
GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0);
/*配置EXTI线0上出现下降沿，则产生中断*/
EXTI_InitStructure.EXTI_Line = EXTI_Line0;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
EXTI_GenerateSWInterrupt(EXTI_Line0);
}