stm32 USART_IT_IDLE中断 一帧数据

USART_IT_IDLE中断，是串口收到一帧数据后，发生的中断。也可以叫做一包数据

USART_IT_IDLE和USART_IT_RXNE区别
当接收到1个字节，会产生USART_IT_RXNE中断
当接收到一帧数据，就会产生USART_IT_IDLE中断

清中断方法

1//USART_IT_RXNE
2USART_ClearITPendingBit(USART1, USART_IT_RXNE);
3
4//USART_IT_IDLE
5USART1->SR; //先读SR寄存器
6USART1->DR; //再读DR寄存器

使用举例

1u8 count;
2u8 flag;
3
4void uart_init(u32 bound)
5{
6    ...
7
8    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
9    USART_ITConfig(USART1, USART_IT_IDLE, ENABLE);
10
11    ...
12}
13
14void USART1_IRQHandler(void)
15{
16    u8 r;
17
18    if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
19    {
20        USART_ClearITPendingBit(USART1, USART_IT_RXNE); //只USART_ReceiveData也可以
21
22        //r = USART_ReceiveData(USART1);
23
24        count++;
25    }
26    else if(USART_GetFlagStatus(USART1, USART_FLAG_IDLE) != RESET)
27    {
28        USART1->SR;
29        USART1->DR;
30
31        flag = 1;
32    }
33}
34
35int main()
36{
37    while(1)
38    {
39        if(flag == 1)
40        {
41            printf("count %d\r\n", count);
42
43            flag = 0;
44            count = 0;
45        }
46
47        delay_ms(10);
48    }
49}

实验现象