應用：
STM32F405，
串口使用DMA接收，接收資料大小不定，
問題：我通過上位機給STM發送資料(資料大小不定，小于256)，第一次發送時，接收正常
之后再發送時，能夠進入串口中斷，但沒有資料，讀到的dma_cnt一直是256，這個可能的原因是什么呢？
主要程式如下： RECVBUFF_SIZE=256
void Debug_USART_Config(void)
{
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=DEBUG_PREE_PRIO;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = DEBUG_SUB_PRIO;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
USART_Init(DEBUG_USART, &USART_InitStructure);
USART_ITConfig(DEBUG_USART, USART_IT_IDLE, ENABLE);
USART_DMACmd(DEBUG_USART,USART_DMAReq_Rx,ENABLE);
USART_Cmd(DEBUG_USART, ENABLE);
DMA_DeInit(DEBUG_USART_DMA_STREAM);
while (DMA_GetCmdStatus(DEBUG_USART_DMA_STREAM) != DISABLE){}
DMA_InitStructure.DMA_Channel = DEBUG_USART_DMA_CHANNEL;
DMA_InitStructure.DMA_PeripheralBaseAddr = DEBUG_USART_DR_BASE;
DMA_InitStructure.DMA_Memory0BaseAddr = (u32)RecvBuff;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = RECVBUFF_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_Init(DEBUG_USART_DMA_STREAM, &DMA_InitStructure);
DMA_Cmd(DEBUG_USART_DMA_STREAM, ENABLE);
while (DMA_GetCmdStatus(DEBUG_USART_DMA_STREAM) != ENABLE){}
}
void USART1_IRQHandler(void)
{
uint16_t dma_cnt;
if(USART_GetITStatus(DEBUG_USART, USART_IT_IDLE) != RESET)
{
USART_ReceiveData(DEBUG_USART);
dma_cnt = DMA_GetCurrDataCounter(DEBUG_USART_DMA_STREAM);
uart1_rev_len =RECVBUFF_SIZE-dma_cnt;
if(uart1_rev_len != 0)
{
uart_parse(RecvBuff);
hw_memset(RecvBuff,0,sizeof(RecvBuff));
}
USART_ClearITPendingBit(DEBUG_USART,USART_IT_IDLE);
DMA_Cmd(DEBUG_USART_DMA_STREAM, DISABLE );
while (DMA_GetCmdStatus(DEBUG_USART_DMA_STREAM) != DISABLE){}
DMA_SetCurrDataCounter(DEBUG_USART_DMA_STREAM,RECVBUFF_SIZE);
DMA_Cmd(DEBUG_USART_DMA_STREAM, ENABLE);
}
}
uj5u.com熱心網友回復：
uart_parse(RecvBuff); 這是什么東西轉載請註明出處，本文鏈接：https://www.uj5u.com/qita/224616.html
標籤：單片機/工控
上一篇：485電平
下一篇：比亞迪 芯片引腳 求解。