本帖最后由 yangzi8000 于 2019-2-12 11:42 编辑
F1使用串口3 DMA空闲中断,设置缓冲区100个字节,发现每次接收到》100个字节才产生一次空闲中断,如何修改设置成接收不定长字节就能空闲中断,贴代码:
void uart_init(u32 bound)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); //??USART1,GPIOA??
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //??DMA??
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE);//??USART2??
USART_DeInit(USART3); //????1
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //??????
GPIO_Init(GPIOB, &GPIO_InitStructure); //???PA9
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????
GPIO_Init(GPIOB, &GPIO_InitStructure);
//Usart1 NVIC ??
NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?????3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //????3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ????
NVIC_Init(&NVIC_InitStructure); //??????????VIC???
//USART ?????
USART_InitStructure.USART_BaudRate = bound;//?????9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;//???8?????
USART_InitStructure.USART_StopBits = USART_StopBits_1;//?????
USART_InitStructure.USART_Parity = USART_Parity_No;//??????
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//????????
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //????
USART_Init(USART3, &USART_InitStructure); //?????
USART_ITConfig(USART3, USART_IT_IDLE, ENABLE);//??????
USART_DMACmd(USART3,USART_DMAReq_Rx,ENABLE); //????1 DMA??
USART_Cmd(USART3, ENABLE); //????
//???DMA??
DMA_DeInit(DMA1_Channel3); //?DMA???5????????? ??1????DMA??5
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART3->DR; //DMA??ADC???
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)RxBuffer3; //DMA?????
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; //??????,??????????
DMA_InitStructure.DMA_BufferSize = 100; //DMA???DMA?????
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //?????????
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //?????????
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //?????8?
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; //?????8?
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //?????????
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; //DMA?? x??????
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA??x????????????
DMA_Init(DMA1_Channel3, &DMA_InitStructure); //??DMA_InitStruct?????????DMA???
DMA_Cmd(DMA1_Channel3, ENABLE); //????DMA??
}
u8 flag1=0;
void USART3_IRQHandler(void)
{
if(USART_GetFlagStatus(USART3,USART_IT_IDLE)!= RESET)
{
u8 num;
num = USART3->SR;
num = USART3->DR; //?USART_IT_IDLE??
DMA_Cmd(DMA1_Channel3,DISABLE); //??DMA
num = 100 - DMA_GetCurrDataCounter(DMA1_Channel3); //??????????
RxBuffer3[num] = ' ';
DMA1_Channel3->CNDTR=100; //??????????
DMA_Cmd(DMA1_Channel3,ENABLE); //??DMA
flag1=1; //????????1
}
}
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曰,进一次中断几us没有了,你当cpu资源无限啊。
你用波特率算过字节传输时间吗?单就这一个串口中断来说这几us相对于字节传输的时间算个屁,你其它应用中断也很密集频繁,对资源要求极高则另当别论。
复制代码的时候不小心删除了 ,这个是有的 if(USART_GetFlagStatus(USART3,USART_IT_IDLE)!= RESET)
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