定时器触发AD采样+DMA传输，这样配置DMA只能传输一轮么？

void ADC1_Sample_Configuration(void)

 {        

        ADC_InitTypeDef        ADC_InitStructure;

        DMA_InitTypeDef         DMA_InitStructure;

        TIM_OCInitTypeDef                TIM_OCInitStructure;

         TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure; 

        TIM_DeInit(TIM2);

        TIM_TimeBaseStructure.TIM_Period = 1999;

         TIM_TimeBaseStructure.TIM_Prescaler = 342;         

         TIM_TimeBaseStructure.TIM_ClockDivision = 0;

         TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

         TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);          

         TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;

         TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

         TIM_OCInitStructure.TIM_Pulse = 0x7F;

            TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;

           TIM_OC2Init(TIM2, &TIM_OCInitStructure);

         TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable); 

         TIM_ARRPreloadConfig(TIM2, ENABLE);

         TIM_Cmd(TIM2, ENABLE);



        DMA_DeInit(DMA1_Channel1);

        DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;

        DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&ADC_Buffer[0];

        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;

        DMA_InitStructure.DMA_BufferSize = 256;

        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

        DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;

        DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;

        DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; 

        DMA_InitStructure.DMA_Priority = DMA_Priority_High;

        DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

        DMA_Init(DMA1_Channel1, &DMA_InitStructure);

        DMA_Cmd(DMA1_Channel1, ENABLE);

 

        ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;

        ADC_InitStructure.ADC_ScanConvMode = DISABLE;

        ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;

        ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_CC2;        

        ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;//右对齐

        ADC_InitStructure.ADC_NbrOfChannel = 1;//转换通道为通道一

        ADC_Init(ADC1, &ADC_InitStructure);

        ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_71Cycles5);

          ADC_DMACmd(ADC1, ENABLE);

        ADC_Cmd(ADC1, ENABLE);

         ADC_ResetCalibration(ADC1);

          while(ADC_GetResetCalibrationStatus(ADC1)); 

         ADC_StartCalibration(ADC1); 

         while(ADC_GetCalibrationStatus(ADC1)); 

         ADC_ExternalTrigConvCmd( ADC1, ENABLE);

} 

 if(DMA_GetFlagStatus(DMA1_FLAG_TC1) != RESET)

{  

   。。。。。。。。。。。

   。。。。。。。。。。。

    DMA_ClearFlag(DMA1_FLAG_TC1);

}