STM32F4库函数初始化系列：DMA串口接收

 1 void _UART2_Configuration(void)
 2 {
 3   USART_InitTypeDef USART_InitStructure;
 4 
 5   USART_OverSampling8Cmd(USART2, ENABLE);  
 6   USART_InitStructure.USART_BaudRate = 19200;
 7   USART_InitStructure.USART_WordLength = USART_WordLength_8b;
 8   USART_InitStructure.USART_StopBits = USART_StopBits_1;
 9   USART_InitStructure.USART_Parity = USART_Parity_No;
10   USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
11   USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
12   USART_Init(USART2, &USART_InitStructure);
13 
14   USART_DMACmd(USART2, USART_DMAReq_Rx, ENABLE);
15 
16   DMA_Cmd(DMA1_Stream5, ENABLE); 
17 
18   USART_Cmd(USART2, ENABLE);  
19 }
20 
21 void _DMA_Configuration(void) 
22 { 
23   DMA_InitTypeDef DMA_InitStructure; 
24 　DMA_InitStructure.DMA_Channel = DMA_Channel_4;  
25   DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(USART2->DR);
26   DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)_Compass_Value;
27   DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
28   DMA_InitStructure.DMA_BufferSize = 3;
29   DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
30   DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
31   DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
32   DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
33   DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
34   DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
35   DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;         
36   DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
37   DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
38   DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
39   DMA_Init(DMA1_Stream5, &DMA_InitStructure);
40 
41   /* DMA2_Stream0 enable */
42   DMA_Cmd(DMA1_Stream5, ENABLE);
43 }