high speed fdcan stm32g431

[Tomuello]

Hi, i'm dealing with fdcan and have problems with high speeds, 1Mbps works good, but 8Mbps (which works in loopback mode) doesn't, I tried with delay compensation, but didn't work, or maybe i used it wrong way?

static void MX_FDCAN1_Init(void)

{

/* USER CODE BEGIN FDCAN1_Init 0 */

/* USER CODE END FDCAN1_Init 0 */

/* USER CODE BEGIN FDCAN1_Init 1 */

/* USER CODE END FDCAN1_Init 1 */

hfdcan1.Instance = FDCAN1;

hfdcan1.Init.ClockDivider = FDCAN_CLOCK_DIV2;

hfdcan1.Init.FrameFormat = FDCAN_FRAME_FD_BRS;

hfdcan1.Init.Mode = FDCAN_MODE_EXTERNAL_LOOPBACK;

hfdcan1.Init.AutoRetransmission = ENABLE;

hfdcan1.Init.TransmitPause = DISABLE;

hfdcan1.Init.ProtocolException = ENABLE;

hfdcan1.Init.NominalPrescaler = 1;

hfdcan1.Init.NominalSyncJumpWidth = 1;

hfdcan1.Init.NominalTimeSeg1 = 3;

hfdcan1.Init.NominalTimeSeg2 = 3;

hfdcan1.Init.DataPrescaler = 1;

hfdcan1.Init.DataSyncJumpWidth = 3;

hfdcan1.Init.DataTimeSeg1 = 3;

hfdcan1.Init.DataTimeSeg2 = 3;

hfdcan1.Init.StdFiltersNbr = 1;

hfdcan1.Init.ExtFiltersNbr = 0;

hfdcan1.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;

if (HAL_FDCAN_Init(&hfdcan1) != HAL_OK)

{

Error_Handler();

}

/* USER CODE BEGIN FDCAN1_Init 2 */

FDCAN_FilterTypeDef sFilterConfig;

// Configure the filter to accept all messages with Standard ID 0x321

sFilterConfig.IdType = FDCAN_STANDARD_ID;

sFilterConfig.FilterIndex = 0; // Use the first filter bank

sFilterConfig.FilterType = FDCAN_FILTER_MASK; // Specify the filter type

sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXFIFO0; // Store matching messages in RX FIFO 0

sFilterConfig.FilterID1 = 0x103; // filter

sFilterConfig.FilterID2 = 0x103; // mask

if (HAL_FDCAN_ConfigFilter(&hfdcan1, &sFilterConfig) != HAL_OK) {

// Handle error

}

HAL_FDCAN_ConfigGlobalFilter(&hfdcan1,

FDCAN_REJECT, // Reject non-matching Standard ID messages

FDCAN_REJECT, // Reject non-matching Extended ID messages

FDCAN_REJECT_REMOTE, // Reject remote frames with Standard ID

FDCAN_REJECT_REMOTE); // Reject remote frames with Extended ID

/* Configure and enable Tx Delay Compensation : TdcOffset = DataTimeSeg1*DataPrescaler */

HAL_FDCAN_ConfigTxDelayCompensation(&hfdcan1, 3, 0);

HAL_FDCAN_EnableTxDelayCompensation(&hfdcan1);

/* USER CODE END FDCAN1_Init 2 */

}

[SofLit · Accepted solution]

Hello,

Nominal bit time Should not exceed 1Mb/s. Only Data phase could reach 8Mb/s for STM32 MCUs.

[Tomuello]

Does it mean that only DATA in the frame goes with 8Mbps and other with 1Mbps?

[SofLit]

Yes.

Nominal phase: max 1Mb/s

Data phase: max 8Mb/s: this is for STM32. Also it depends on the transceiver bandwidth you're using.