关于STM32中CAN1_RX0_IRQn和CAN1_RX1_IRQn的使用

“如果你用的CAN引脚是PA11和PA12，接收中断用CAN1_RX0_IRQn。如果CAN引脚用的是PB8和PB9，也就是用重定义的引脚，接收中断用CAN1_RX1_IRQn。由于PA11和PA12也是USB的引脚，所以非互联型且带CAN控制器的微控制器的库文件在起名字时用了USB_LP_CAN1_RX0_IRQn。”

以上内容参考于网络，后经证实，以上说法是不正确的，理由如下：

STM32有2个3级深度的接收缓冲区：FIFO0和FIFO1，每个FIFO都可以存放3个完整的报文，它们完全由硬件来管理。如果是来自FIFO0的接收中断，则用CAN1_RX0_IRQn中断来处理。如果是来自FIFO1的接收中断，则用CAN1_RX1_IRQn中断来处理。在CAN的初始化配置过程中，用CAN_FilterFIFOAssignment来选择要使用FIFO。

示例如下：

1. 配置过滤器
CAN_FilterInitStructure.CAN_FilterNumber = 0;

CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;

CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_32bit;

CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;

CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;

CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;

CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;

CAN_FilterInitStructure.CAN_FilterFIFOAssignment = 0; //关联FIFO0

CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;

CAN_FilterInit(&CAN_FilterInitStructure);

CAN_FilterInitStructure.CAN_FilterNumber = 14;

CAN_FilterInitStructure.CAN_FilterFIFOAssignment = 1; //关联FIFO1

CAN_FilterInit(&CAN_FilterInitStructure);

2. 开启CAN中断

/* IT Configuration for CAN1 */

CAN_ITConfig(CAN1, CAN_IT_FMP0, ENABLE);

CAN_ITConfig(CAN1, CAN_IT_FMP1, ENABLE);

/* IT Configuration for CAN2 */

CAN_ITConfig(CAN2, CAN_IT_FMP0, ENABLE);

CAN_ITConfig(CAN2, CAN_IT_FMP1, ENABLE);

3. 中断处理函数

void CAN1_RX0_IRQHandler(void)

{
CAN_Receive(CAN1, CAN_FIFO0, &CAN1_RxMsg);

//
}

void CAN1_RX1_IRQHandler(void)

{
CAN_Receive(CAN1, CAN_FIFO1, &CAN1_RxMsg);

//
}

void CAN2_RX0_IRQHandler(void)

{

CAN_Receive(CAN2, CAN_FIFO0, &CAN2_RxMsg);
//
}

void CAN2_RX1_IRQHandler(void)

{
CAN_Receive(CAN2, CAN_FIFO1, &CAN2_RxMsg);
//
}