Use case: Clock calibration (interrupt)

The main differences between HAL1 and HAL2 in handling FDCAN clock calibration interrupts are as follows:

  • Activate notifications

    • In HAL1, calibration interrupts are enabled using HAL_FDCAN_ActivateNotification() with interrupts FDCAN_IT_CALIB_STATE_CHANGED and FDCAN_IT_CALIB_WATCHDOG_EVENT.

    • In HAL2, these interrupts are enabled using HAL_FDCAN_CCU_EnableInterrupts(). This is enough since the clock calibration has its own dedicated interrupts line.

  • Interrupt handler

    • In HAL1, all interrupts are handled by HAL_FDCAN_IRQHandler().

    • In HAL2, line 0 and line 1 interrupts are handled by HAL_FDCAN_IRQHandler(), while clock calibration interrupts are handled by HAL_FDCAN_CCU_IRQHandler().

  • Calibration callback

    • In HAL1, the HAL_FDCAN_ClockCalibrationCallback() is triggered with specific flags (FDCAN_IT_CALIB_STATE_CHANGED or FDCAN_IT_CALIB_WATCHDOG_EVENT) to indicate calibration state changes or watchdog events.

    • In HAL2, two callbacks are provided:

      HAL_FDCAN_CCU_CalibrationCallback() to indicate calibration state changes.

      HAL_FDCAN_CCU_CalibrationWatchdogCallback() to indicate that the watchdog expired before calibration completed.

Sequence diagram

@startuml participant App as "User Application" participant "<font color=black><b>HAL FDCAN" as FDCAN #19DD3A participant "NVIC" as NVIC#AliceBlue participant "FDCAN Hardware System" as FDCAN_HW == FDCAN Clock calibration Configuration == App -> FDCAN: HAL_FDCAN_ConfigClockCalibration(&hfdcan, &sCcuConfig) FDCAN -> FDCAN_HW: Setup Clock Calibration Unit (CCU) FDCAN_HW --> FDCAN: CCU configured FDCAN --> App: <color green>HAL_OK == Configure Reception Filters and enable interrupt == App -> FDCAN: HAL_FDCAN_ConfigFilter(&hfdcan, &sFilterConfig) [Calibration Filter] note right Configure at least one filter for both calibration frames to enter the BASIC_CALIBRATED and the PRECISION_CALIBRATED with IsCalibrationMsg = 1 endnote FDCAN --> App: <color green>HAL_OK App -> FDCAN: HAL_FDCAN_ConfigInterruptLines(&hfdcan, FDCAN_IT_RX_BUFFER_NEW_MESSAGE \n , FDCAN_INTERRUPT_LINE0) FDCAN --> App: <color green>HAL_OK App -> FDCAN: HAL_FDCAN_ActivateNotification(&hfdcan, FDCAN_IT_RX_BUFFER_NEW_MESSAGE \n | FDCAN_IT_CALIB_STATE_CHANGED \n | FDCAN_IT_CALIB_WATCHDOG_EVENT, FDCAN_TX_BUFFER0) FDCAN --> App: <color green>HAL_OK == FDCAN Clock calibration Process == App -> FDCAN: HAL_FDCAN_Start(&hfdcan) FDCAN --> App: <color green>HAL_OK hNote over FDCAN_HW: The FDCAN in <color red><b>Restricted Operation Mode</b></color> hnote over FDCAN_HW <font color=red><b>BASIC_CALIBRATION or NOT_CALIBRATED</b> end note FDCAN_HW <- : FDCAN Rx buffer new calibration message note left The configured filter <index> accept the calibration message end note FDCAN_HW --> NVIC: Rx Buffer New Message interrupt \n **FDCAN_IT0_IRQ** NVIC -> FDCAN: HAL_FDCAN_IRQHandler() FDCAN -> App: HAL_FDCAN_RxBufferNewMessageCallback() FDCAN <-- App: NVIC <-- FDCAN: FDCAN_HW <-- NVIC: alt watchdog counter reaches zero before state changed FDCAN_HW --> FDCAN_HW: Watchdog counter reaches zero \n before CCU state changed FDCAN_HW-->NVIC: CCU watchdog event \n **FDCAN_CCU_IRQ** NVIC ->FDCAN: HAL_FDCAN_IRQHandler() hnote over FDCAN_HW <font color=red><b>NOT_CALIBRATED</b> end note FDCAN -> App: HAL_FDCAN_ClockCalibrationCallback(&hfdcan, FDCAN_IT_CALIB_WATCHDOG_EVENT) hNote over App:<font color=red><b>failed else state changed before watchdog counter reaches zero FDCAN_HW --> FDCAN_HW: CCU state changed before\nWatchdog counter reaches zero FDCAN_HW-->NVIC: CCU state change event \n **FDCAN_CCU_IRQ** NVIC ->FDCAN: HAL_FDCAN_IRQHandler() FDCAN -> App: HAL_FDCAN_ClockCalibrationCallback(&hfdcan, FDCAN_IT_CALIB_STATE_CHANGED) App --> FDCAN: FDCAN --> NVIC: hnote over FDCAN_HW <font color=orange><b>BASIC_CALIBRATION</b> end note end 'Precision Calibration Process' FDCAN_HW <- : FDCAN **second** Rx buffer new message\n(From quartz node) starts with at least "1010" note left The configured filter <index> accept the calibration message end note FDCAN_HW --> NVIC: Rx Buffer New Message interrupt \n **FDCAN_IT0_IRQ** NVIC -> FDCAN: HAL_FDCAN_IRQHandler() FDCAN -> App: HAL_FDCAN_RxBufferNewMessageCallback() FDCAN <-- App: NVIC <-- FDCAN: FDCAN_HW <-- NVIC: alt watchdog counter reaches zero before state changed FDCAN_HW --> FDCAN_HW: Watchdog counter reaches zero \n before CCU state changed FDCAN_HW-->NVIC: CCU watchdog event \n **FDCAN_CCU_IRQ** NVIC ->FDCAN: HAL_FDCAN_IRQHandler() hnote over FDCAN_HW <font color=red><b>NOT_CALIBRATED</b> end note FDCAN -> App: HAL_FDCAN_ClockCalibrationCallback(&hfdcan, FDCAN_IT_CALIB_WATCHDOG_EVENT) hNote over App:<font color=red><b>failed else state changed before watchdog counter reaches zero FDCAN_HW --> FDCAN_HW: CCU state changed before\nWatchdog counter reaches zero FDCAN_HW-->NVIC: CCU state change event \n **FDCAN_CCU_IRQ** NVIC ->FDCAN: HAL_FDCAN_IRQHandler() hnote over FDCAN_HW <font color=green><b>PRECISION_CALIBRATED</b> end note FDCAN -> App: HAL_FDCAN_ClockCalibrationCallback(&hfdcan, FDCAN_IT_CALIB_STATE_CHANGED) hNote over App:<font color=green><b>Success App -> FDCAN: HAL_FDCAN_ExitRestrictedOperationMode hNote over FDCAN_HW: The FDCAN in <color green><b>Normal Operation Mode</b></color> App <-- FDCAN:<color green>HAL_OK end Note over App: The FDCAN is calibrated and ready to be used for communication. @enduml

Code snippet

HAL1

HAL2 

HAL_FDCAN_Start(&hfdcan);

CcuConfig.ClockCalibration     = ENABLE;


CcuConfig.MinOscClkPeriods     = 4;
CcuConfig.CalFieldLength       = FDCAN_CALIB_FIELD_LENGTH_64;
CcuConfig.TimeQuantaPerBitTime = 20;
CcuConfig.WatchdogStartValue   = 40;

HAL_FDCAN_ConfigClockCalibration(&hfdcan, &CcuConfig);

HAL_FDCAN_ConfigInterruptLines(&hfdcan,
                               FDCAN_IT_RX_BUFFER_NEW_MESSAGE
                               FDCAN_INTERRUPT_LINE0);

HAL_FDCAN_ActivateNotification(&hfdcan,
                               FDCAN_IT_RX_BUFFER_NEW_MESSAGE
                               | FDCAN_IT_CALIB_STATE_CHANGED
                               | FDCAN_IT_CALIB_WATCHDOG_EVENT,
                                 FDCAN_TX_BUFFER0);

HAL_FDCAN_Start(&hfdcan);

hal_fdcan_ccu_clock_route_t clock_route = HAL_FDCAN_CCU_CLOCK_ROUTE_CALIBRATION;
HAL_FDCAN_CCU_SetClockRouting(&hfdcan, clock_route);

ccu_config.min_osc_clk_periods          = 4;
ccu_config.calibration_field_length     = HAL_FDCAN_CCU_FIELD_LENGTH_64;
ccu_config.time_quanta_per_bit_time     = 20;
ccu_config.watchdog_start_value         = 40;

HAL_FDCAN_CCU_SetConfigCalibrationUnit(&hfdcan, &ccu_config);

HAL_FDCAN_SetInterruptsToLine(&hfdcan,
               HAL_FDCAN_IT_RX_BUFFER_NEW_MESSAGE
               , HAL_FDCAN_IT_LINE_0);

HAL_FDCAN_EnableInterruptLines(&hfdcan, HAL_FDCAN_IT_LINE_0);

HAL_FDCAN_EnableInterrupts(&hfdcan,
                           HAL_FDCAN_IT_RX_BUFFER_NEW_MESSAGE
                           );
HAL_FDCAN_CCU_EnableInterrupts(&hfdcan,
                               HAL_FDCAN_CCU_IT_CALIBRATION_STATE_CHANGE
                             | HAL_FDCAN_CCU_IT_CALIBRATION_WATCHDOG_EVENT
                               );

Key changes

  1. HAL2 manages clock calibration interrupts through dedicated CCU APIs.

  2. HAL2 introduces a dedicated IRQ handler for CCU interrupts.