# HRCAP Module

The High Resolution Enhanced Capture (HRCAP) API provides a set of functions for configuring and using the high resolution capability of the HRCAP module. The functions provided allow for the setup and configuration of the high resolution capture capability. The necessary APIs to configure the high resolution capture calibration hardware are also provided.

group `hrcap_api`

  Defines

  `HRCAP_GLOBAL_CALIBRATION_INTERRUPT` 0x1U

    Global calibration interrupt flag

  `HRCAP_CALIBRATION_DONE` 0x2U

    Calibration done flag

  `HRCAP_CALIBRATION_PERIOD_OVERFLOW` 0x4U

    Calibration period overflow flag

  Enums

  enum `HRCAP_CalibrationClockSource`

    Values that can be passed to HRCAP_getCalibrationClockPeriod() as the clockSource parameter.

    Values:

    enumerator `HRCAP_CALIBRATION_CLOCK_SYSCLK` = 0x0

      Use SYSCLK for period match.

    enumerator `HRCAP_CALIBRATION_CLOCK_HRCLK` = 0x4

      Use HRCLK for period match.

  enum `HRCAP_ContinuousCalibrationMode`

    Values that can be passed to HRCAP_setCalibrationMode(), as the continuousMode parameter.

    Values:

    enumerator `HRCAP_CONTINUOUS_CALIBRATION_DISABLED` = 0x00

      Continuous calibration disabled.

    enumerator `HRCAP_CONTINUOUS_CALIBRATION_ENABLED` = 0x20

      Continuous calibration enabled.

  Functions

  void `HRCAP_enableHighResolution`(uint32_t base)

    enables HRCAP.

    This function enables High Resolution Capture module.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Note

      High resolution clock must be enabled before High Resolution Module is enabled.

    Return

      None.

  void `HRCAP_disableHighResolution`(uint32_t base)

    Disables HRCAP.

    This function disable High Resolution Capture module.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Return

      None.

  void `HRCAP_enableHighResolutionClock`(uint32_t base)

    Enables high resolution clock.

    This function enables High Resolution clock.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Return

      None.

  void `HRCAP_disbleHighResolutionClock`(uint32_t base)

    Disables High resolution clock.

    This function disables High Resolution clock.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Return

      None.

  void `HRCAP_startCalibration`(uint32_t base)

    Starts calibration.

    This function starts calibration.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Return

      None.

  void `HRCAP_setCalibrationMode`(uint32_t base)

    Sets the calibration mode.

    This function sets the the calibration mode by turning on continuous calibration.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Return

      None.

  void `HRCAP_enableCalibrationInterrupt`(uint32_t base, uint16_t intFlags)

    Enables calibration interrupt.

    This function enables HRCAP calibration interrupt flags. Valid values for intFlags are:

    - HRCAP_CALIBRATION_DONE - Calibration done interrupt.

    - HRCAP_CALIBRATION_PERIOD_OVERFLOW - Calibration period overflow check interrupt.

      Return

        None.

    Parameters

      - `base`: is the base address of the HRCAP module.

      - `intFlags`: is the calibration interrupt flags to be enabled.

  void `HRCAP_disableCalibrationInterrupt`(uint32_t base, uint16_t intFlags)

    Disables calibration interrupt source.

    This function disables HRCAP calibration interrupt flags. Valid values for intFlags are:

    - HRCAP_CALIBRATION_DONE - Calibration done interrupt.

    - HRCAP_CALIBRATION_PERIOD_OVERFLOW - Calibration period check interrupt.

      Return

        None.

    Parameters

      - `base`: is the base address of the HRCAP module.

      - `intFlags`: is the calibration interrupt flags to be disabled.

  uint16_t `HRCAP_getCalibrationFlags`(uint32_t base)

    Returns the calibration interrupt source.

    This function returns the HRCAP calibration interrupt source.

    Parameters

      - `base`: is the base address of the HRCAP module.

    Return

      Returns the HRCAP interrupt that has occurred. The following are valid return values.

      - HRCAP_GLOBAL_CALIBRATION_INTERRUPT - Global calibration interrupt.

      - HRCAP_CALIBRATION_DONE - Calibration done interrupt.

      - HRCAP_CALIBRATION_PERIOD_OVERFLOW - Calibration period overflow interrupt.

    Note

      - User can check if a combination of the interrupts have occurred by ORing the above return values.

  void `HRCAP_clearCalibrationFlags`(uint32_t base, uint16_t flags)

    Clears calibration flags.

    This function clears HRCAP calibration flags. The following are valid values for flags.

    - HRCAP_GLOBAL_CALIBRATION_INTERRUPT - Global calibration interrupt.

    - HRCAP_CALIBRATION_DONE - Calibration done flag.

    - HRCAP_CALIBRATION_PERIOD_OVERFLOW - Calibration period overflow flag.

    Parameters

      - `base`: is the base address of the HRCAP module.

      - `flags`: is the calibration flags to be cleared.

    Return

      None.

  bool `HRCAP_isCalibrationBusy`(uint32_t base)

    Return the Calibration status

    This function returns the calibration status.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Return

      This functions returns true if the calibration is in process,false if there is no active calibration.

  void `HRCAP_forceCalibrationFlags`(uint32_t base, uint16_t flag)

    Force a software based calibration

    This function forces a software based calibration done flag. The following are valid values for flag.

    - HRCAP_CALIBRATION_DONE - Calibration done flag.

    - HRCAP_CALIBRATION_PERIOD_OVERFLOW - Calibration period overflow flag.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

      - `flag`: is the calibration flag source.

    Return

      None.

  void `HRCAP_setCalibrationPeriod`(uint32_t base, uint32_t sysclkHz)

    Sets the calibration period count

    This function sets the calibration period count value to achieve a period of 1.6 milliseconds given the SYSCLK frequency in Hz (the

    sysclkHz parameter).
    Parameters

      - `base`: is the base address of the HRCAP instance used.

      - `sysclkHz`: is the rate of the SYSCLK in Hz.

    Return

      None.

  uint32_t `HRCAP_getCalibrationClockPeriod`(uint32_t base, HRCAP_CalibrationClockSource clockSource)

    Returns the calibration clock period

    This function returns the period match value of the calibration clock. The return value has a valid count when a period match occurs.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

      - `clockSource`: is the calibration clock source (HRCAP_CALIBRATION_CLOCK_SYSCLK or HRCAP_CALIBRATION_CLOCK_HRCLK).

    Return

      This function returns the captured value of the clock counter specified by clockSource.

  float32_t `HRCAP_getScaleFactor`(uint32_t base)

    Calculates the scale factor

    This function reads the SYSCLK and HRCLK calibration periods and then uses them to calculate the scale factor.

    Parameters

      - `base`: is the base address of the HRCAP instance used.

    Return

      This function returns the calculated scale factor.

  float32_t `HRCAP_convertEventTimeStampNanoseconds`(uint32_t timeStamp, float32_t scaleFactor)

    Returns event time stamp in nanoseconds

    This function converts a raw CAP time stamp (the

    timeStamp parameter) to nanoseconds using the provided scale factor (the scaleFactor parameter).
    Parameters

      - `timeStamp`: is a raw time stamp count returned by ECAP_getEventTimeStamp().

      - `scaleFactor`: is the calculated scale factor returned by HRCAP_getScaleFactor().

    Return

      Returns the converted time stamp in nanoseconds.

The code for this module is contained in driverlib/hrcap.c, with driverlib/hrcap.h containing the API declarations for use by applications.