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- 2017-7-18
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- 3 小时
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4金钱
我用stm32f103的开发板做实验，加了uart3的代码之后，会导致外部中断没反应，麻烦各位前辈帮忙看看，实在没思路。
详情如下：
1）设PE0为外部中断，下降沿出发，中断程序如下：
[mw_shl_code=cpp,true]//中断初始化
void exti_init(void)
{
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
//使能AFIO时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
//PE0中断设置
GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource0); //下降沿触发
EXTI_InitStructure.EXTI_Line=EXTI_Line0;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_Init(&EXTI_InitStructure);
//中断优先级设置
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; //设置通道
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能通道
NVIC_Init(&NVIC_InitStructure);
}
static u16 count = 0;
//中断处理函数
void EXTI0_IRQHandler(void)
{
count ++;
if (count == 20) {
count = 0;
LED1 = !LED1;
}
EXTI_ClearITPendingBit(EXTI_Line0);
}
[/mw_shl_code]
2）main函数如下，烧录到板子上之后，能进入中断处理程序，工作正常：
[mw_shl_code=cpp,true] int main(void)
{
u8 key;
u16 i = 0;
delay_init(); //延时函数初始化
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//设置中断优先级分组为组2：2位抢占优先级，2位响应优先级
uart_init(115200); //串口初始化为115200
LED_Init(); //初始化与LED连接的硬件接口
exti_init(); //中断初始化
while(1){
delay_ms(10);
i++;
if (i == 50) {
i = 0;
LED0 = !LED0;
}
}
}[/mw_shl_code]
3）然后我再添加了一段初始化uart3的代码，就导致无法进入中断程序（即中断没反应）：
usart3.c =>
[mw_shl_code=cpp,true]//初始化IO 串口3
//pclk1 CLK1时钟频率(Mhz)
//bound:波特率
void usart3_init(u32 bound)
{
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); // GPIOB时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE); //串口3时钟使能
//USART_DeInit(USART3); //复位串口3
//USART3_TX PB10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; //PB10
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_Init(GPIOB, &GPIO_InitStructure); //初始化PB10
//USART3_RX PB11
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
GPIO_Init(GPIOB, &GPIO_InitStructure); //初始化PB11
USART_InitStructure.USART_BaudRate = bound;//波特率一般设置为9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //收发模式
USART_Init(USART3, &USART_InitStructure); //初始化串口 3
USART_Cmd(USART3, ENABLE); //使能串口
//使能接收中断
USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);//开启中断
//设置中断优先级
NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2 ;//抢占优先级3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器
TIM7_Int_Init(1000-1,7200-1); //10ms中断
USART3_RX_STA=0; //清零
TIM_Cmd(TIM7,DISABLE); //关闭定时器7
}[/mw_shl_code]
接着把usart3_init(115200);这句代码添加到main函数中=>
[mw_shl_code=cpp,true] int main(void)
{
u8 key;
u16 i = 0;
delay_init(); //延时函数初始化
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//设置中断优先级分组为组2：2位抢占优先级，2位响应优先级
uart_init(115200); //串口初始化为115200
LED_Init(); //初始化与LED连接的硬件接口
usart3_init(115200); //初始化串口3
exti_init(); //中断初始化
while(1){
delay_ms(10);
i++;
if (i == 50) {
i = 0;
LED0 = !LED0;
}
}
}[/mw_shl_code]
4）我把usart3_init函数的以下代码注释掉之后，中断又能工作了：
[mw_shl_code=cpp,true] //初始化IO 串口3
//pclk1CLK1时钟频率(Mhz)
//bound:波特率
void usart3_init(u32 bound)
{
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); // GPIOB时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE); //串口3时钟使能
//USART_DeInit(USART3); //复位串口3
//USART3_TX PB10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; //PB10
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_Init(GPIOB, &GPIO_InitStructure); //初始化PB10
//USART3_RX PB11
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
GPIO_Init(GPIOB, &GPIO_InitStructure); //初始化PB11
//
// USART_InitStructure.USART_BaudRate = bound;//波特率一般设置为9600;
// USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
// USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
// USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
// USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
// USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //收发模式
//
// USART_Init(USART3, &USART_InitStructure); //初始化串口 3
USART_Cmd(USART3, ENABLE); //使能串口
//使能接收中断
USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);//开启中断
//设置中断优先级
NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2 ;//抢占优先级3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC寄存器
TIM7_Int_Init(1000-1,7200-1); //10ms中断
USART3_RX_STA=0; //清零
TIM_Cmd(TIM7,DISABLE); //关闭定时器7
}[/mw_shl_code]
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发表于 2017-7-18 17:33:34
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