cancel
Showing results for 
Search instead for 
Did you mean: 

STM32G474 FDCAN3 bit timing

ma.alam9
Associate III

Hello All,

I am trying to send some classic CAN messages via the FDCAN3 module on STM32G474CE device. I have only pins for FDCAN3 free. My FDCAN clock is PCLK1 with a frequency of 64MHz.

When I try to transmit a CAN message, firstly there is no transmission on the line (as seen from the oscilloscope and PCAN-Explorer software.

My questions are: 1. Can I even use FDCAN3 alone to transmit messages? Is it necessary to enable FDCAN1 for it or something?

  1. What should be the bit timing register values for nominal and data bit timing registers to achieve a Baud rate of 250 KBits per sec. Again, I want to send only normal classic CANopen messages and no CANFD messages.

Here is how CubeMX has programmed the configuration registers

hfdcan3.Instance = FDCAN3;

 hfdcan3.Init.FrameFormat = FDCAN_FRAME_CLASSIC;

 hfdcan3.Init.Mode = FDCAN_MODE_NORMAL;

 hfdcan3.Init.AutoRetransmission = DISABLE;

 hfdcan3.Init.TransmitPause = DISABLE;

 hfdcan3.Init.ProtocolException = DISABLE;

 hfdcan3.Init.NominalPrescaler = 16;

 hfdcan3.Init.NominalSyncJumpWidth = 1;

 hfdcan3.Init.NominalTimeSeg1 = 13;

 hfdcan3.Init.NominalTimeSeg2 = 2;

 hfdcan3.Init.DataPrescaler = 16;

 hfdcan3.Init.DataSyncJumpWidth = 1;

 hfdcan3.Init.DataTimeSeg1 = 13;

 hfdcan3.Init.DataTimeSeg2 = 2;

 hfdcan3.Init.StdFiltersNbr = 1;

 hfdcan3.Init.ExtFiltersNbr = 0;

 hfdcan3.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;

 if (HAL_FDCAN_Init(&hfdcan3) != HAL_OK)

 {

  Error_Handler();

 }

Any help on this?

1 ACCEPTED SOLUTION

Accepted Solutions
1 REPLY 1
SKacp.1
Senior II