串口DMA接收问题？

穆义 · 发表于 2016-12-31 16:07:18

求助：我用USART1接收数据，将数据用DMA存放在内存的BUFF中，通过轮询查看USART1的DMA接收完成标志，判断BUFF是否存满，然后在用串口4将存的BUFF中的数据读出来。现在问题是：程序下载后，只能通过串口4收到一次数据（只能最开始检查到一次USART1的DMA接收完成标志），之后DMA接收完成标志一直为0，串口4再也收不到数据了，请问是什么原因？（在网上，论坛看了很多相关的问题，但都没有解决此问题）

下面是main函数程序：
u8 PlayLoadByte,streamByte;
u8 USART1_RECEIVE_BUF[USART1_RECEIVE_MAX];
int main(void)
{
int i;
delay_init();
UART4_Init(9600);
USART1_Init(57600);
USART1_DMARX_Init((u32)&USART1->DR,(u32)USART1_RECEIVE_BUF,USART1_RECEIVE_MAX);
// UART4_DMATX_Init((u32)&UART4->DR,(u32)&PlayLoadByte,1);
while(1)
{
USART1_DMA_Enable();
while(1)
{
if(DMA_GetFlagStatus(DMA1_FLAG_TC5)==SET)
{
DMA_Cmd(DMA1_Channel5,DISABLE);
DMA_ClearFlag(DMA1_FLAG_TC5);
USART_GetFlagStatus(UART4,USART_FLAG_TC);
for(i=0;i<(USART1_RECEIVE_MAX-DMA_GetCurrDataCounter(DMA1_Channel5));i++)
{
streamByte = USART1_RECEIVE_BUF[i];
USART_SendData(UART4,streamByte);
while(USART_GetFlagStatus(UART4,USART_FLAG_TC)!=SET);
}
break;
}
delay_ms(100);
LED0=!LED0;
}
delay_ms(100);
LED1=!LED1;
}
}

穆义 · 发表于 2016-12-31 16:08:36

下面是USART配置：
void UART4_Init(u32 bound)
{
USART_InitTypeDef USART_InitStruct;
GPIO_InitTypeDef GPIO_InitStruct;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE);//ê1ÄüUSART4ê±Öó
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC|RCC_APB2Periph_GPIOE,ENABLE);

//UART4μÄIO¿úÅäÖÃ
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_10;//PC10ÎaUART4μÄTX¶Ë
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;//íÆÃa¸′óÃêä3öÄ￡ê½
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOC,&GPIO_InitStruct);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_11;//PC11ÎaUART4μÄRX¶Ë
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN_FLOATING;//¸¡¿ÕêäèëÄ￡ê½
GPIO_Init(GPIOC,&GPIO_InitStruct);

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOE,&GPIO_InitStruct);

USART_InitStruct.USART_BaudRate = bound;//′®¿ú2¨ìØÂê
USART_InitStruct.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;//êÕ/·￠Ä￡ê½
USART_InitStruct.USART_Parity = USART_Parity_No;//ÎTÆæÅ¼D￡ÑéÎ»
USART_InitStruct.USART_StopBits = USART_StopBits_1;//ò»¸öí￡Ö1Î»
USART_InitStruct.USART_WordLength = USART_WordLength_8b;//8Î»êy¾Y3¤¶è
USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//ÎTó2¼tá÷¿ØÖÆ
USART_Init(UART4,&USART_InitStruct);//3õê¼»ˉ′®¿ú4

USART_Cmd(UART4,ENABLE);//ê1Äü′®¿ú4
}
/*****************************************************************************************************

*****************************************************************************************************/
void USART1_Init(u32 bound)
{
USART_InitTypeDef USART_InitStruct;
GPIO_InitTypeDef GPIO_InitStruct;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB,ENABLE);

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_9;//PC10ÎaUART4μÄTX¶Ë
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;//íÆÃa¸′óÃêä3öÄ￡ê½
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStruct);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_10;//PC11ÎaUART4μÄRX¶Ë
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN_FLOATING;//¸¡¿ÕêäèëÄ￡ê½
GPIO_Init(GPIOA,&GPIO_InitStruct);

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB,&GPIO_InitStruct);

USART_InitStruct.USART_BaudRate = bound;//′®¿ú2¨ìØÂê
USART_InitStruct.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;//êÕ/·￠Ä￡ê½
USART_InitStruct.USART_Parity = USART_Parity_No;//ÎTÆæÅ¼D￡ÑéÎ»
USART_InitStruct.USART_StopBits = USART_StopBits_1;//ò»¸öí￡Ö1Î»
USART_InitStruct.USART_WordLength = USART_WordLength_8b;//8Î»êy¾Y3¤¶è
USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//ÎTó2¼tá÷¿ØÖÆ
USART_Init(USART1,&USART_InitStruct);//3õê¼»ˉ′®¿ú4

USART_Cmd(USART1,ENABLE);//ê1Äü′®¿ú4
}
下面是DMA配置：
void UART4_DMATX_Init(u32 cpar,u32 cmar,u16 cndtr)
{
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE); //ê1ÄüDMA2′«êä

DMA_DeInit(DMA2_Channel5);//½«DMA2μÄí¨μà5¼Ä′æÆ÷ÖØéèÎaè±ê¡Öμ

DMA1_MEM_LEN = cndtr;
DMA_InitStructure.DMA_BufferSize = cndtr;//DMAí¨μà′«êäμÄêy¾Yá¿
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;//êy¾Y′«êä·½Ïò￡¬′óÄú′æμ½íaéè
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;//2»¿aÆôÄú′æμ½Äú′æ′«êä
DMA_InitStructure.DMA_MemoryBaseAddr = cmar;//DMAÄú′æ»ùμØÖ·
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//êy¾Y¿í¶èÎa8Î»
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//Äú′æμØÖ·¼Ä′æÆ÷μYÔö
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;//1¤×÷ÔúÕy3￡Ä￡ê½￡¬2»Ñ-»·2é¼ˉêy¾Y
DMA_InitStructure.DMA_PeripheralBaseAddr =cpar;//DMAíaéè»ùμØÖ·
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;//êy¾Y¿í¶èÎa8Î»
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //íaéèμØÖ·¼Ä′æÆ÷2»±ä
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;//′ËDMAí¨μàóD×î¸ßóÅÏèè¨
DMA_Init(DMA2_Channel5,&DMA_InitStructure);//3õê¼»ˉDMA2í¨μà5￡¨UART4_TX￡©
}
/*********************************************************************************
*********************************************************************************/
void USART1_DMARX_Init(u32 cpar,u32 cmar,u16 cndtr)
{
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

DMA_DeInit(DMA1_Channel5);

DMA1_MEM_LEN = cndtr;
DMA_InitStructure.DMA_BufferSize = cndtr;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_InitStructure.DMA_MemoryBaseAddr = cmar;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_PeripheralBaseAddr =cpar;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_Init(DMA1_Channel5,&DMA_InitStructure);
}
/******************************************************************************/
/******************************************************************************/
void UART4_DMA_Enable(void)
{
DMA_Cmd(DMA2_Channel5,DISABLE);
DMA_SetCurrDataCounter(DMA2_Channel5,1);
USART_DMACmd(UART4,USART_DMAReq_Tx,ENABLE);
DMA_Cmd(DMA2_Channel5,ENABLE);
}
/**********************************************************************************
**********************************************************************************/
void USART1_DMA_Enable(void)
{
DMA_Cmd(DMA1_Channel5,DISABLE);
DMA_SetCurrDataCounter(DMA1_Channel5,USART1_RECEIVE_MAX);
((DMA_Channel_TypeDef*)DMA1_Channel5)->CMAR=(u32)USART1_RECEIVE_BUF;
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);
DMA_Cmd(DMA1_Channel5,ENABLE);
}