stm32 can实验部分总结

天马 · 发表于 2011-12-1 10:25:05

1.CAN接收需要开中断，用中断方式接收（查询也可以），发送不用中断。

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2.接收中断可以用CAN_ITConfig 打开，但不能用CAN_ClearITPendingBit 关闭，因为这个里面没有接收中断CAN_IT_FMP0。

@brief Clears the CANx's interrupt pending bits.

* @param CANx: where x can be 1 or 2 to to select the CAN peripheral.

* @param CAN_IT: specifies the interrupt pending bit to clear.

* - CAN_IT_TME

* - CAN_IT_FF0

* - CAN_IT_FOV0

* - CAN_IT_FF1

* - CAN_IT_FOV1

* - CAN_IT_WKU

* - CAN_IT_SLK

* - CAN_IT_EWG

* - CAN_IT_EPV

* - CAN_IT_BOF

* - CAN_IT_LEC

* - CAN_IT_ERR

3.接收中断如果用库函数CAN_Receive，则不用关中断，因为函数在最后释放邮箱，CANx->RF0R |= CAN_RF0R_RFOM0;
stm32f10x_can.c中如下函数：
void CAN_Receive(CAN_TypeDef* CANx, uint8_t FIFONumber, CanRxMsg* RxMessage)
{
/* Check the parameters */
assert_param(IS_CAN_ALL_PERIPH(CANx));
assert_param(IS_CAN_FIFO(FIFONumber));
/* Get the Id */
RxMessage->IDE = (uint8_t)0x04 & CANx->sFIFOMailBox[FIFONumber].RIR;
if (RxMessage->IDE == CAN_Id_Standard)
{
    RxMessage->StdId = (uint32_t)0x000007FF & (CANx->sFIFOMailBox[FIFONumber].RIR >> 21);
}
else
{
    RxMessage->ExtId = (uint32_t)0x1FFFFFFF & (CANx->sFIFOMailBox[FIFONumber].RIR >> 3);
}

RxMessage->RTR = (uint8_t)0x02 & CANx->sFIFOMailBox[FIFONumber].RIR;
/* Get the DLC */
RxMessage->DLC = (uint8_t)0x0F & CANx->sFIFOMailBox[FIFONumber].RDTR;
/* Get the FMI */
RxMessage->FMI = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDTR >> 8);
/* Get the data field */
RxMessage->Data[0] = (uint8_t)0xFF & CANx->sFIFOMailBox[FIFONumber].RDLR;
RxMessage->Data[1] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDLR >> 8);
RxMessage->Data[2] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDLR >> 16);
RxMessage->Data[3] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDLR >> 24);
RxMessage->Data[4] = (uint8_t)0xFF & CANx->sFIFOMailBox[FIFONumber].RDHR;
RxMessage->Data[5] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDHR >> 8);
RxMessage->Data[6] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDHR >> 16);
RxMessage->Data[7] = (uint8_t)0xFF & (CANx->sFIFOMailBox[FIFONumber].RDHR >> 24);
/* Release the FIFO */
/* Release FIFO0 */
if (FIFONumber == CAN_FIFO0)
{
    CANx->RF0R |= CAN_RF0R_RFOM0;
}
/* Release FIFO1 */
else /* FIFONumber == CAN_FIFO1 */
{
    CANx->RF1R |= CAN_RF1R_RFOM1;
}
}