stm32之can总线过滤器研究

stm32的can总线的配置如下：

      CAN_InitStructure.CAN_TTCM=DISABLE;//禁止时间触发通信模式
      CAN_InitStructure.CAN_ABOM=DISABLE;
      CAN_InitStructure.CAN_AWUM=DISABLE;
      CAN_InitStructure.CAN_NART=DISABLE;//CAN报文只被发送1次，不管发送的结果如何（成功、出错或仲裁丢失）
      CAN_InitStructure.CAN_RFLM=DISABLE;
      CAN_InitStructure.CAN_TXFP=DISABLE;
      CAN_InitStructure.CAN_Mode=CAN_Mode_Normal;
      //CAN_Mode_LoopBack
      //CAN_Mode_Normal
      CAN_InitStructure.CAN_SJW=CAN_SJW_1tq;
      CAN_InitStructure.CAN_BS1=CAN_BS1_5tq;//1--16
      CAN_InitStructure.CAN_BS2=CAN_BS2_2tq;//1--8
      CAN_InitStructure.CAN_Prescaler=2;

      CAN_Init(&CAN_InitStructure);

       /* CAN filter init */
      CAN_FilterInitStructure.CAN_FilterNumber=0;//选择过滤器0
      CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;//指定过滤器被设置为标识符屏蔽模式
      CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;//给出过滤器位宽为32位

下面根据设置的参数不同来决定can总线can总线的配置情况：

1、对扩展数据帧进行过滤:(只接收扩展数据帧)
      CAN_FilterInitStructure.CAN_FilterIdHigh   = (((u32)slave_id<<3)&0xFFFF0000)>>16;
      CAN_FilterInitStructure.CAN_FilterIdLow   = (((u32)slave_id<<3)|CAN_ID_EXT|CAN_RTR_DATA)&0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdHigh  = 0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdLow   = 0xFFFF;
(注：标准帧数据帧、标准远程帧和扩展远程帧均被过滤)
2、对扩展远程帧过滤:(只接收扩展远程帧)
      CAN_FilterInitStructure.CAN_FilterIdHigh   = (((u32)slave_id<<3)&0xFFFF0000)>>16;
      CAN_FilterInitStructure.CAN_FilterIdLow   = (((u32)slave_id<<3)|CAN_ID_EXT|CAN_RTR_REMOTE)&0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdHigh  = 0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdLow   = 0xFFFF;

3、对标准远程帧过滤:(只接收标准远程帧)
      CAN_FilterInitStructure.CAN_FilterIdHigh   = (((u32)slave_id<<21)&0xffff0000)>>16;
      CAN_FilterInitStructure.CAN_FilterIdLow   = (((u32)slave_id<<21)|CAN_ID_STD|CAN_RTR_REMOTE)&0xffff;
      CAN_FilterInitStructure.CAN_FilterMaskIdHigh  = 0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdLow   = 0xFFFF;
4、对标准数据帧过滤:(只接收标准数据帧)
      CAN_FilterInitStructure.CAN_FilterIdHigh   = (((u32)slave_id<<21)&0xffff0000)>>16;
      CAN_FilterInitStructure.CAN_FilterIdLow   = (((u32)slave_id<<21)|CAN_ID_STD|CAN_RTR_DATA)&0xffff;
      CAN_FilterInitStructure.CAN_FilterMaskIdHigh  = 0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdLow   = 0xFFFF;

5、对扩展帧进行过滤:(扩展帧不会被过滤掉)
      CAN_FilterInitStructure.CAN_FilterIdHigh   = (((u32)slave_id<<3)&0xFFFF0000)>>16;
      CAN_FilterInitStructure.CAN_FilterIdLow   = (((u32)slave_id<<3)|CAN_ID_EXT)&0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdHigh  = 0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdLow   = 0xFFFC;
6、对标准帧进行过滤:(标准帧不会被过滤掉)
      CAN_FilterInitStructure.CAN_FilterIdHigh   = (((u32)slave_id<<21)&0xffff0000)>>16;
      CAN_FilterInitStructure.CAN_FilterIdLow   = (((u32)slave_id<<21)|CAN_ID_STD)&0xffff;
      CAN_FilterInitStructure.CAN_FilterMaskIdHigh  = 0xFFFF;
      CAN_FilterInitStructure.CAN_FilterMaskIdLow   = 0xFFFC;
注：slave_id为要过滤的id号。