Use case: Communication in interrupt mode

The FDCAN interrupt management has been updated to use a more modular approach.

• Interrupt to line configuration:

  In HAL1, the configuration of FDCAN interrupt lines is performed using the HAL_FDCAN_ConfigInterruptLines() function. When interrupt grouping is supported by the given STM32 device, grouped interrupt flags such as FDCAN_IT_GROUP_SMSG and FDCAN_IT_GROUP_RX_FIFO0 are collectively assigned to the chosen interrupt line (line 0 and/or line 1). If interrupt grouping is not supported by the device, individual interrupt sources like FDCAN_IT_TX_COMPLETE and FDCAN_IT_RX_FIFO0_NEW_MESSAGE are assigned directly to the chosen interrupt line (line 0 and/or line 1).

  In HAL2, when the interrupt grouping feature is available on the STM32 device, HAL_FDCAN_SetInterruptGroupsToLine() is used to assign grouped interrupts (e.g., HAL_FDCAN_IT_GROUP_STATUS_MSG and HAL_FDCAN_IT_GROUP_RX_FIFO_0) to the chosen interrupt line (line 0 and/or line 1). When interrupt grouping is not available, HAL_FDCAN_SetInterruptsToLine() is used to assign individual interrupts (e.g., HAL_FDCAN_IT_TX_COMPLETE and HAL_FDCAN_IT_RX_FIFO_0_NEW_MSG) to the chosen interrupt line (line 0 and/or line 1).

Interrupt grouping feature	HAL1	HAL2
Available	Use HAL_FDCAN_ConfigInterruptLines() with grouped interrupts (e.g., FDCAN_IT_GROUP_SMSG)	Use HAL_FDCAN_SetInterruptGroupsToLine() to assign grouped interrupts (e.g., HAL_FDCAN_IT_GROUP_STATUS_MSG)
Not available	Use HAL_FDCAN_ConfigInterruptLines() with individual interrupts (e.g., FDCAN_IT_TX_COMPLETE)	Use HAL_FDCAN_SetInterruptsToLine() to assign individual interrupts (e.g., HAL_FDCAN_IT_TX_COMPLETE)

• Interrupt activation

  In HAL1, the function HAL_FDCAN_ActivateNotification() is used to enable specific FDCAN interrupt notifications in a single call, meaning it enables both the requested interrupts and the interrupt line(s) (line 0 and/or line 1) on which the corresponding interrupts are set.

  In HAL2, interrupt management is designed to be more granular and modular:

  • HAL_FDCAN_EnableInterruptLines() is used to activate the interrupt line(s) (line 0 and/or line 1).

  • HAL_FDCAN_EnableInterrupts() enables interrupt sources (e.g. HAL_FDCAN_IT_RX_FIFO_0_NEW_MSG).

  • For transmit complete interrupts like FDCAN_IT_TX_COMPLETE, the dedicated function HAL_FDCAN_EnableTxBufferCompleteInterrupts() must also be called to enable the corresponding buffer interrupts.

  • Similarly, for transmit abort interrupts such as FDCAN_IT_TX_ABORT_COMPLETE, the function HAL_FDCAN_EnableTxBufferCancellationInterrupts() must also be called.

  • Additionally, HAL_FDCAN_CCU_EnableInterrupts() is provided to enable clock calibration unit interrupts.

For more details see HAL FDCAN enables interrupt notifications..

Sequence diagram

HAL1 sequence diagram HAL2 sequence diagram

Code snippet

HAL1

HAL2

/* if interrupt grouping available */ HAL_FDCAN_ConfigInterruptLines(&hfdcan, FDCAN_IT_GROUP_SMSG | FDCAN_IT_GROUP_RX_FIFO0, FDCAN_INTERRUPT_LINE0); /* else */ HAL_FDCAN_ConfigInterruptLines(&hfdcan, FDCAN_IT_TX_COMPLETE | FDCAN_IT_RX_FIFO0_NEW_MESSAGE, FDCAN_INTERRUPT_LINE0); HAL_FDCAN_ActivateNotification(&hfdcan, FDCAN_IT_TX_COMPLETE | FDCAN_IT_RX_FIFO0_NEW_MESSAGE, FDCAN_TX_BUFFER0); HAL_FDCAN_Start(&hfdcan); /* Prepare FDCAN transmit message header */ TxHeader.Identifier = 0x111; TxHeader.IdType = FDCAN_STANDARD_ID; TxHeader.TxFrameType = FDCAN_DATA_FRAME; TxHeader.DataLength = FDCAN_DLC_BYTES_8; TxHeader.ErrorStateIndicator = FDCAN_ESI_ACTIVE; TxHeader.BitRateSwitch = FDCAN_BRS_ON; TxHeader.FDFormat = FDCAN_FD_CAN; TxHeader.TxEventFifoControl = FDCAN_NO_TX_EVENTS; TxHeader.MessageMarker = 0; HAL_FDCAN_AddMessageToTxFifoQ(&hfdcan, &TxHeader, &TxData[0]); while (TransmissionCompleteFlag == 0); if (Notification_flag == 1) { HAL_FDCAN_GetRxMessage(&hfdcan, FDCAN_RX_FIFO0, &RxHeader, RxData); Notification_flag = 0; } void HAL_FDCAN_RxFifo0Callback(FDCAN_HandleTypeDef *hfdcan, uint32_t RxFifo0ITs) { if((RxFifo0ITs & FDCAN_IT_RX_FIFO0_NEW_MESSAGE) != RESET) { Notification_flag = 1; } } void HAL_FDCAN_TxBufferCompleteCallback(FDCAN_HandleTypeDef *hfdcan, uint32_t BufferIndexes) { TransmissionCompleteFlag = 1U; }

/* if interrupt grouping */ HAL_FDCAN_SetInterruptGroupsToLine(&hfdcan, HAL_FDCAN_IT_GROUP_STATUS_MSG | HAL_FDCAN_IT_GROUP_RX_FIFO_0 , HAL_FDCAN_IT_LINE_0 ); /* else */ HAL_FDCAN_SetInterruptsToLine(&hfdcan, HAL_FDCAN_IT_TX_COMPLETE | HAL_FDCAN_IT_RX_FIFO_0_NEW_MSG , HAL_FDCAN_IT_LINE_0 ); HAL_FDCAN_EnableInterruptLines(&hfdcan, HAL_FDCAN_IT_LINE_0); HAL_FDCAN_EnableTxBufferCompleteInterrupts(&hfdcan, HAL_FDCAN_IT_TX_CPLT_BUFFER_0); HAL_FDCAN_EnableInterrupts(&hfdcan, HAL_FDCAN_IT_TX_COMPLETE | HAL_FDCAN_IT_RX_FIFO_0_NEW_MSG); HAL_FDCAN_Start(&hfdcan); /* Prepare FDCAN transmit message header */ tx_element_header.b.identifier = 0x111, tx_element_header.b.identifier_type = HAL_FDCAN_ID_STANDARD, tx_element_header.b.frame_type = HAL_FDCAN_FRAME_DATA, tx_element_header.b.data_length = HAL_FDCAN_DATA_LEN_CAN_FDCAN_8_BYTE, tx_element_header.b.error_state_indicator = HAL_FDCAN_ERROR_STATE_IND_ACTIVE, tx_element_header.b.bit_rate_switch = HAL_FDCAN_BIT_RATE_SWITCH_ON, tx_element_header.b.frame_format = HAL_FDCAN_HEADER_FRAME_FORMAT_FD_CAN, tx_element_header.b.event_fifo_control = HAL_FDCAN_FIFO_STORE_TX_EVENTS, tx_element_header.b.message_marker = 0U, HAL_FDCAN_ReqTransmitMsgFromFIFOQ(hfdcan, &tx_element_header, pTxData); while (TransmissionCompleteFlag == 0); if (Notification_flag == 1) { HAL_FDCAN_GetReceivedMessage(hfdcan, HAL_FDCAN_RX_FIFO_0, &rx_element_header, RxBuffer); ReceptionFlag = 0; } static void HAL_FDCAN_RxFifo0Callback(hal_fdcan_handle_t *hfdcan, uint32_t rx_fifo0_interrupts) { if((rx_fifo0_interrupts & HAL_FDCAN_IT_RX_FIFO_0_NEW_MSG) != RESET) { Notification_flag = 1; } } static void HAL_FDCAN_TxBufferCompleteCallback(hal_fdcan_handle_t *hfdcan, uint32_t buffer_indexes) { TransmissionCompleteFlag = 1U; }

Key changes

1. HAL2 splits notification configuration into separate APIs to configure interrupts and interrupt line(s).

2. HAL2 provides dedicated APIs for enabling Tx buffer complete interrupts.

Related examples in HAL2

Example Name	Description
example_hal_fdcan_two_boards_com_it_controller/example_hal_fdcan_two_boards_com_it_responder	How to handle an infinite number of transmit-receive transactions between two boards based on the FDCAN-bus protocol with the HAL API, in interrupt mode.