void  Adc_Init(void)
{   
  GPIO_InitTypeDef  GPIO_InitStructure;
        ADC_CommonInitTypeDef ADC_CommonInitStructure;
        ADC_InitTypeDef       ADC_InitStructure;
       


        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);//ê1ÄüGPIOAê±Öó
        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);//ê1ÄüGPIOCê±Öó
        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE);//ê1ÄüGPIOAê±Öó
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE); //ê1ÄüADC1ê±Öó
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC2, ENABLE); //ê1ÄüADC2ê±Öó
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE); //ê1ÄüADC3ê±Öó

         //Ïè3õê¼»ˉADC1í¨μà5 IO¿ú
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_4;//ê1ÄüáËADC1μÄ0￡¬1￡¬2í¨μà
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;//Ä￡Äaêäèë
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;//2»′øéÏÏÂà-
  GPIO_Init(GPIOA, &GPIO_InitStructure);//3õê¼»ˉ
       
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2;//ê1ÄüáËADC10￡11￡¬¬12í¨μà
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;//Ä￡Äaêäèë
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;//2»′øéÏÏÂà-
  GPIO_Init(GPIOC, &GPIO_InitStructure);//3õê¼»ˉ  
       
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7|GPIO_Pin_8;//ê1ÄüáËADC10￡11￡¬¬12í¨μà
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;//Ä￡Äaêäèë
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;//2»′øéÏÏÂà-
  GPIO_Init(GPIOF, &GPIO_InitStructure);//3õê¼»ˉ  

        RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC1,ENABLE);          //ADC1¸′λ
        RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC1,DISABLE);        //¸′λ½áêø         
        RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC2,ENABLE);          //ADC2¸′λ
        RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC2,DISABLE);        //¸′λ½áêø       
        RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC3,ENABLE);          //ADC2¸′λ
        RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC3,DISABLE);        //¸′λ½áêø               

       
  ADC_CommonInitStructure.ADC_Mode = ADC_TripleMode_RegSimult;//¶àá￠Ä￡ê½
  ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_15Cycles;//ὸö2éÑù½×¶ÎÖ®¼äμÄÑó3ù5¸öê±Öó
  ADC_CommonInitStructure.ADC_DMAAccessMode =  ADC_DMAAccessMode_2; //DMAÄ￡꽶t
  ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div4;//Ô¤·ÖÆμ4·ÖÆμ¡￡ADCCLK=PCLK2/4=84/4=21Mhz,ADCê±Öó×îoÃ2»òa3¬1y36Mhz
  ADC_CommonInit(&ADC_CommonInitStructure);//3õê¼»ˉ
       
  ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;//12λÄ￡ê½
  ADC_InitStructure.ADC_ScanConvMode = ENABLE;//é¨ÃèÄ￡ê½
  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;//¿aÆôá¬Dø×a»»
  ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;//½ûÖ1′￥·￠¼ì2a￡¬ê1óÃèí¼t′￥·￠
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;//óò¶ÔÆë       
  ADC_InitStructure.ADC_NbrOfConversion = 1;//3¸ö×a»»Ôú1æÔòDòáDÖD ò2¾íêÇÖ»×a»»1æÔòDòáD3
  ADC_Init(ADC1, &ADC_InitStructure);//ADC3õê¼»ˉ
        ADC_Init(ADC2, &ADC_InitStructure);//ADC3õê¼»ˉ
        ADC_Init(ADC3, &ADC_InitStructure);//ADC3õê¼»ˉ
       
  ADC_DMACmd(ADC1, ENABLE);
        ADC_Cmd(ADC1, ENABLE);//¿aÆôAD×a»»Æ÷
  ADC_DMACmd(ADC2, ENABLE);
        ADC_Cmd(ADC2, ENABLE);//¿aÆôAD×a»»Æ÷       
        ADC_DMACmd(ADC3, ENABLE);
        ADC_Cmd(ADC3, ENABLE);//¿aÆôAD×a»»Æ÷               
       
        ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_3Cycles);
        //ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_3Cycles);
//        ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 3, ADC_SampleTime_3Cycles);
        ADC_RegularChannelConfig(ADC2, ADC_Channel_10, 1, ADC_SampleTime_3Cycles);
//        ADC_RegularChannelConfig(ADC2, ADC_Channel_11, 2, ADC_SampleTime_3Cycles);
        //ADC_RegularChannelConfig(ADC2, ADC_Channel_12, 3, ADC_SampleTime_3Cycles);
        ADC_RegularChannelConfig(ADC3, ADC_Channel_4, 1, ADC_SampleTime_3Cycles);
        //ADC_RegularChannelConfig(ADC3, ADC_Channel_5, 2, ADC_SampleTime_3Cycles);
        //ADC_RegularChannelConfig(ADC3, ADC_Channel_6, 3, ADC_SampleTime_3Cycles);



  ADC_SoftwareStartConv(ADC1);       
  ADC_SoftwareStartConv(ADC2);       
        ADC_SoftwareStartConv(ADC3);               
}               

/*配置DMA*/
  DMA_InitStructure.DMA_Channel = chx;  //í¨μàÑ¡Ôñ
  DMA_InitStructure.DMA_PeripheralBaseAddr = par;//DMAíaéèμØÖ·
  DMA_InitStructure.DMA_Memory0BaseAddr = mar;//DMA ′æ′￠Æ÷0μØÖ·
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory ;//íaéèμ½′æ′￠Æ÷Ä￡ê½Ä￡ê½
  DMA_InitStructure.DMA_BufferSize = ndtr;//êy¾Y′«êäá¿
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//íaéè·ÇÔöá¿Ä￡ê½
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//′æ′￠Æ÷Ôöá¿Ä￡ê½
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;//íaéèêy¾Y3¤¶è:16λ
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;//′æ′￠Æ÷êy¾Y3¤¶è:16λ
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;// ê1óÃÑ-»·Ä￡ê½
  DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;//ÖDμèóÅÏ輶
  DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;         
  DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
  DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;//′æ′￠Æ÷í»·￠μ￥′Î′«êä
  DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;//íaéèí»·￠μ￥′Î′«êä
  DMA_Init(DMA_Streamx, &DMA_InitStructure);//3õê¼»ˉDMA Stream

主程序中的DMA配置
MYDMA_Config(DMA2_Stream0,DMA_Channel_0,(u32)&ADC->CDR,(u32)&adcx,6);
        MYDMA_Enable(DMA2_Stream0,6);

目前的设定是ADC1 3.3V也就是0xFF，ADC2是0V也就是0X00左右，ADC3是3.3V
选择的是ADC的规则同步模式，DMA模式2，应该是第一个数据是ADC1,2的，第二个是ADC1,3的，第三个是3，2的，可是我这个到了第二组之后就一直是1.3的值不变了，这是为什么