STM32

有如下程序片段：

#defineADC1_DR_Address((u32)0x4001244C)

#defineADC3_DR_Address((u32)0x40013C4C)

.

.

DMA_DeInit(DMA1_Channel1);

DMA_InitStructure.DMA_PeripheralBaseAddr=ADC1_DR_Address;

DMA_InitStructure.DMA_MemoryBaseAddr=(u32)&ADC1ConvertedValue;

DMA_InitStructure.DMA_DIR=DMA_DIR_PeripheralSRC;

DMA_InitStructure.DMA_BufferSize=1;

DMA_InitStructure.DMA_PeripheralInc=DMA_PeripheralInc_Disable;

DMA_InitStructure.DMA_MemoryInc=DMA_MemoryInc_Disable;

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=ENABLE;

ADC_InitStructure.ADC_ContinuousConvMode=ENABLE;

ADC_InitStructure.ADC_ExternalTrigConv=ADC_ExternalTrigConv_None;

ADC_InitStructure.ADC_DataAlign=ADC_DataAlign_Right;

ADC_InitStructure.ADC_NbrOfChannel=14;

ADC_Init(ADC1,&ADC_InitStructure);

ADC_RegularChannelConfig(ADC1,ADC_Channel_14,1,ADC_SampleTime_28Cycles5);

ADC_DMACmd(ADC1,ENABLE);

ADC_Cmd(ADC1,ENABLE);

请问该程序在AD采样时,应从哪个引脚（是不是PA1?）输入信号?

如果想从PA7输入信号,应如何修改程序?