FDCAN 可变波特率全速模式问题

opsd999 · 发表于 2022-4-23 14:02:06

板：两块stm32h750VBcan芯片：microchip MCP2562FD，支持 2,5,8Mbps

两板信号各有2个6N137隔离光耦

问题：FDCAN时钟80Mhz，当FDCAN仲裁段波特率设为1Mbps，数据段波特率设为2Mbps，运行正常，当FDCAN数据段波特率继续上调至5Mbps或者8Mbps时，正常模式出现通讯异常，然后将模式改为外部环回模式，接收板接收到了信号。查看单片机应用手册，外部环回模式会忽视ACK错误。应该是接收板应答问题，有大神能讲解一下吗。对FDCAN这么多寄存器不是很了解，这大概是哪方面导致的。

代码：
初始化部分
void MX_FDCAN2_Init(void)
{
  /* USER CODE BEGIN FDCAN2_Init 0 */
      FDCAN_FilterTypeDef sFilterConfig;
  /* USER CODE END FDCAN2_Init 0 */
  /* USER CODE BEGIN FDCAN2_Init 1 */
  /* USER CODE END FDCAN2_Init 1 */
  hfdcan2.Instance = FDCAN2;
  hfdcan2.Init.FrameFormat = FDCAN_FRAME_FD_BRS;
  //hfdcan2.Init.Mode = FDCAN_MODE_EXTERNAL_LOOPBACK;
      hfdcan2.Init.Mode = FDCAN_MODE_NORMAL;
  hfdcan2.Init.AutoRetransmission = ENABLE;
  hfdcan2.Init.TransmitPause = DISABLE;
  hfdcan2.Init.ProtocolException = ENABLE;
  hfdcan2.Init.NominalPrescaler = 1;
  hfdcan2.Init.NominalSyncJumpWidth = 15;
  hfdcan2.Init.NominalTimeSeg1 = 64;
  hfdcan2.Init.NominalTimeSeg2 = 15;
  hfdcan2.Init.DataPrescaler = 1;
  hfdcan2.Init.DataSyncJumpWidth = 2;
  hfdcan2.Init.DataTimeSeg1 = 7;
  hfdcan2.Init.DataTimeSeg2 = 2;
  hfdcan2.Init.MessageRAMOffset = 0;
  hfdcan2.Init.StdFiltersNbr = 1;
  hfdcan2.Init.ExtFiltersNbr = 0;
  hfdcan2.Init.RxFifo0ElmtsNbr = 2;
  hfdcan2.Init.RxFifo0ElmtSize = FDCAN_DATA_BYTES_8;
  hfdcan2.Init.RxFifo1ElmtsNbr = 0;
  hfdcan2.Init.RxFifo1ElmtSize = FDCAN_DATA_BYTES_8;
  hfdcan2.Init.RxBuffersNbr = 0;
  hfdcan2.Init.RxBufferSize = FDCAN_DATA_BYTES_8;
  hfdcan2.Init.TxEventsNbr = 0;
  hfdcan2.Init.TxBuffersNbr = 0;
  hfdcan2.Init.TxFifoQueueElmtsNbr = 2;
  hfdcan2.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;
  hfdcan2.Init.TxElmtSize = FDCAN_DATA_BYTES_8;
  if (HAL_FDCAN_Init(&hfdcan2) != HAL_OK)
  {
Error_Handler();
  }
  /* USER CODE BEGIN FDCAN2_Init 2 */
      sFilterConfig.IdType = FDCAN_STANDARD_ID;
      sFilterConfig.FilterIndex = 0;
      sFilterConfig.FilterType = FDCAN_FILTER_RANGE;
      sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXFIFO0;
      sFilterConfig.FilterID1 = 0x00;
      sFilterConfig.FilterID2 = 0x04;
      HAL_FDCAN_ConfigFilter(&hfdcan2, &sFilterConfig);
      HAL_FDCAN_ConfigFifoWatermark(&hfdcan2,FDCAN_CFG_RX_FIFO0,1);
      HAL_FDCAN_ActivateNotification(&hfdcan2,FDCAN_IT_RX_FIFO0_WATERMARK,0);
      HAL_FDCAN_Start(&hfdcan2);
  /* USER CODE END FDCAN2_Init 2 */
}

发送部分：
if(len>8)
            dl = FDCAN_DLC_BYTES_8;
            else
                     dl = ((uint32_t)len) << 16;
            pTxHeader.Identifier = 1;
            pTxHeader.IdType = FDCAN_STANDARD_ID;
            pTxHeader.TxFrameType = FDCAN_DATA_FRAME;
            pTxHeader.DataLength =  dl;
            pTxHeader.ErrorStateIndicator = FDCAN_ESI_ACTIVE;
            pTxHeader.BitRateSwitch = FDCAN_BRS_ON;
            pTxHeader.FDFormat = FDCAN_FD_CAN;
            pTxHeader.TxEventFifoControl = FDCAN_NO_TX_EVENTS;
            pTxHeader.MessageMarker = 0;
            HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan2, &pTxHeader, can_tx_buf);

接收部分：
void HAL_FDCAN_RxFifo0Callback(FDCAN_HandleTypeDef *hfdcan, uint32_t RxFifo0ITs)
{
      FDCAN_RxHeaderTypeDef pRxHeader;
      if((RxFifo0ITs & FDCAN_IT_RX_FIFO0_WATERMARK) != 0)
      {
            if(HAL_FDCAN_GetRxMessage(hfdcan, FDCAN_RX_FIFO0, &pRxHeader, can_rx_buf) == HAL_OK)
            {
                     HAL_FDCAN_ActivateNotification(hfdcan,FDCAN_IT_RX_FIFO0_WATERMARK,0);
                     cmd = can_rx_buf[0];
                     len = pRxHeader.DataLength >> 16;
                     id = (uint8_t)pRxHeader.Identifier;
                     switch(cmd)
                     {
                              case 1       :
                                                                                                            break;
                              case 2       :
                                                                                                            break;
                              case 3:
                                                                                                            break;
                              case 4       :       HAL_GPIO_WritePin(LED_GPIO_Port,LED_Pin,GPIO_PIN_RESET);
                                                                                                            break;
                              case 5       :
                                                                                                            break;
                              case 9 :
                                                                                                            break;
                     }
            }
      }
}

FDCAN时钟微信截图_20220423132749.png