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最近在學(xué)習(xí)串口的DMA接收，發(fā)現(xiàn)一個(gè)問題，就是RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); 這條時(shí)鐘無論是否開啟，都能正常接收，有沒有高手能解釋下這條語句。具體程序我壓縮包上傳，經(jīng)過測(cè)試串口助手是可以發(fā)送并將收到的信息發(fā)回。請(qǐng)大師們指正，這個(gè)工程未完工，階段測(cè)試可以。
void Serial_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);
// RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);// ???
USART_DeInit(USART1); //復(fù)位串口1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//Usart1 NVIC 配置
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//搶占優(yōu)先級(jí)3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子優(yōu)先級(jí)3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根據(jù)指定的參數(shù)初始化VIC寄存器
//NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_Init(USART1, &USART_InitStructure); //初始化串口
USART_ITConfig(USART1, USART_IT_IDLE, ENABLE);//開啟空閑中斷
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE); //使能串口1 DMA接收
USART_Cmd(USART1,ENABLE); //使能串口
DMA_DeInit(DMA1_Channel5); //將DMA的通道5寄存器重設(shè)為缺省值 串口1對(duì)應(yīng)的是DMA通道5
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART1->DR; //DMA外設(shè)ADC基地址
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)DMA_RX_Buf; //DMA內(nèi)存基地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; //數(shù)據(jù)傳輸方向，從外設(shè)讀取發(fā)送到內(nèi)存
DMA_InitStructure.DMA_BufferSize = DMA_Max_Size; //DMA通道的DMA緩存的大小
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //外設(shè)地址寄存器不變
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //內(nèi)存地址寄存器遞增
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //數(shù)據(jù)寬度為8位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; //數(shù)據(jù)寬度為8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //工作在正常緩存模式
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; //DMA通道 x擁有中優(yōu)先級(jí)
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA通道x沒有設(shè)置為內(nèi)存到內(nèi)存?zhèn)鬏?br />
DMA_Init(DMA1_Channel5, &DMA_InitStructure); //根據(jù)DMA_InitStruct中指定的參數(shù)初始化DMA的通道
USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);
DMA_Cmd(DMA1_Channel5, ENABLE); //正式驅(qū)動(dòng)DMA傳輸
}
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未完工的DMA.zip
2024-7-14 16:36 上傳
點(diǎn)擊文件名下載附件
323.42 KB, 下載次數(shù): 2
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