# EQEP Module

The enhanced quadrature encoder pulse (eQEP) API provides a set of functions to configure an interface to an encoder. The functions provide the ability to configure the device’s eQEP module to properly decode incoming pulse signals, to configure module outputs, and to get direction, position, and speed information. There are also APIs to setup the possible interrupt events that the module can generate.

group `eqep_api`

  Defines

  `EQEP_CONFIG_QUADRATURE` 0x0000U

    Quadrature-clock mode.

  `EQEP_CONFIG_CLOCK_DIR` 0x4000U

    Direction-count mode.

  `EQEP_CONFIG_UP_COUNT` 0x8000U

    Up-count mode, QDIR = 1.

  `EQEP_CONFIG_DOWN_COUNT` 0xC000U

    Down-count mode, QDIR = 0.

  `EQEP_CONFIG_2X_RESOLUTION` 0x0000U

    Count rising and falling edge.

  `EQEP_CONFIG_1X_RESOLUTION` 0x0800U

    Count rising edge only.

  `EQEP_CONFIG_NO_SWAP` 0x0000U

    Do not swap QEPA and QEPB.

  `EQEP_CONFIG_SWAP` 0x0400U

    Swap QEPA and QEPB.

  `EQEP_CONFIG_IGATE_DISABLE` 0x0000U

    Disable gating of Index pulse.

  `EQEP_CONFIG_IGATE_ENABLE` 0x0200U

    Gate the index pin with strobe.

  `EQEP_COMPARE_NO_SYNC_OUT` 0x0000U

    Disable sync output.

  `EQEP_COMPARE_IDX_SYNC_OUT` 0x2000U

    Sync output on index pin.

  `EQEP_COMPARE_STROBE_SYNC_OUT` 0x3000U

    Sync output on strobe pin.

  `EQEP_COMPARE_NO_SHADOW` 0x0000U

    Disable shadow of QPOSCMP.

  `EQEP_COMPARE_LOAD_ON_ZERO` 0x8000U

    Load on QPOSCNT = 0.

  `EQEP_COMPARE_LOAD_ON_MATCH` 0xC000U

    Load on QPOSCNT = QPOSCMP.

  `EQEP_INT_GLOBAL` 0x0001U

    Global interrupt flag.

  `EQEP_INT_POS_CNT_ERROR` 0x0002U

    Position counter error.

  `EQEP_INT_PHASE_ERROR` 0x0004U

    Quadrature phase error.

  `EQEP_INT_DIR_CHANGE` 0x0008U

    Quadrature direction change.

  `EQEP_INT_WATCHDOG` 0x0010U

    Watchdog time-out.

  `EQEP_INT_UNDERFLOW` 0x0020U

    Position counter underflow.

  `EQEP_INT_OVERFLOW` 0x0040U

    Position counter overflow.

  `EQEP_INT_POS_COMP_READY` 0x0080U

    Position-compare ready.

  `EQEP_INT_POS_COMP_MATCH` 0x0100U

    Position-compare match.

  `EQEP_INT_STROBE_EVNT_LATCH` 0x0200U

    Strobe event latch.

  `EQEP_INT_INDEX_EVNT_LATCH` 0x0400U

    Index event latch.

  `EQEP_INT_UNIT_TIME_OUT` 0x0800U

    Unit time-out.

  `EQEP_INT_QMA_ERROR` 0x1000U

    QMA error.

  `EQEP_STS_UNIT_POS_EVNT` 0x0080U

    Unit position event detected.

  `EQEP_STS_DIR_ON_1ST_IDX` 0x0040U

    Direction was clockwise on first index event.

  `EQEP_STS_DIR_FLAG` 0x0020U

    Direction is CW (forward)

  `EQEP_STS_DIR_LATCH` 0x0010U

    Direction was CW on index.

  `EQEP_STS_CAP_OVRFLW_ERROR` 0x0008U

    Capture timer overflow.

  `EQEP_STS_CAP_DIR_ERROR` 0x0004U

    Direction changed between position capture events.

  `EQEP_STS_1ST_IDX_FLAG` 0x0002U

    First index pulse occurred.

  `EQEP_STS_POS_CNT_ERROR` 0x0001U

    Position counter error.

  `EQEP_LATCH_CNT_READ_BY_CPU` 0x0000U

    On position counter read.

  `EQEP_LATCH_UNIT_TIME_OUT` 0x0004U

    On unit time-out event.

  `EQEP_LATCH_RISING_STROBE` 0x0000U

    On rising edge of strobe.

  `EQEP_LATCH_EDGE_DIR_STROBE` 0x0040U

    On rising edge when clockwise, on falling when counter clockwise.

  `EQEP_LATCH_RISING_INDEX` 0x0010U

    On rising edge of index.

  `EQEP_LATCH_FALLING_INDEX` 0x0020U

    On falling edge of index.

  `EQEP_LATCH_SW_INDEX_MARKER` 0x0030U

    On software index marker.

  `EQEP_INIT_DO_NOTHING` 0x0000U

    Action is disabled.

  `EQEP_INIT_RISING_STROBE` 0x0800U

    On rising edge of strobe.

  `EQEP_INIT_EDGE_DIR_STROBE` 0x0C00U

    On rising edge when clockwise, on falling when counter clockwise.

  `EQEP_INIT_RISING_INDEX` 0x0200U

    On rising edge of index.

  `EQEP_INIT_FALLING_INDEX` 0x0300U

    On falling edge of index.

  Enums

  enum `EQEP_PositionResetMode`

    Values that can be passed to EQEP_setPositionCounterConfig() as the mode parameter.

    Values:

    enumerator `EQEP_POSITION_RESET_IDX` = 0x0000

      Reset position on index pulse.

    enumerator `EQEP_POSITION_RESET_MAX_POS` = 0x1000

      Reset position on maximum position.

    enumerator `EQEP_POSITION_RESET_1ST_IDX` = 0x2000

      Reset position on the first index pulse.

    enumerator `EQEP_POSITION_RESET_UNIT_TIME_OUT` = 0x3000

      Reset position on a unit time event.

  enum `EQEP_CAPCLKPrescale`

    Values that can be passed to EQEP_setCaptureConfig() as the capPrescale parameter. CAPCLK is the capture timer clock frequency.

    Values:

    enumerator `EQEP_CAPTURE_CLK_DIV_1` = 0x00

      CAPCLK = SYSCLKOUT/1.

    enumerator `EQEP_CAPTURE_CLK_DIV_2` = 0x10

      CAPCLK = SYSCLKOUT/2.

    enumerator `EQEP_CAPTURE_CLK_DIV_4` = 0x20

      CAPCLK = SYSCLKOUT/4.

    enumerator `EQEP_CAPTURE_CLK_DIV_8` = 0x30

      CAPCLK = SYSCLKOUT/8.

    enumerator `EQEP_CAPTURE_CLK_DIV_16` = 0x40

      CAPCLK = SYSCLKOUT/16.

    enumerator `EQEP_CAPTURE_CLK_DIV_32` = 0x50

      CAPCLK = SYSCLKOUT/32.

    enumerator `EQEP_CAPTURE_CLK_DIV_64` = 0x60

      CAPCLK = SYSCLKOUT/64.

    enumerator `EQEP_CAPTURE_CLK_DIV_128` = 0x70

      CAPCLK = SYSCLKOUT/128.

  enum `EQEP_UPEVNTPrescale`

    Values that can be passed to EQEP_setCaptureConfig() as the evntPrescale parameter. UPEVNT is the unit position event frequency.

    Values:

    enumerator `EQEP_UNIT_POS_EVNT_DIV_1`

      UPEVNT = QCLK/1.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_2`

      UPEVNT = QCLK/2.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_4`

      UPEVNT = QCLK/4.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_8`

      UPEVNT = QCLK/8.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_16`

      UPEVNT = QCLK/16.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_32`

      UPEVNT = QCLK/32.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_64`

      UPEVNT = QCLK/64.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_128`

      UPEVNT = QCLK/128.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_256`

      UPEVNT = QCLK/256.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_512`

      UPEVNT = QCLK/512.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_1024`

      UPEVNT = QCLK/1024.

    enumerator `EQEP_UNIT_POS_EVNT_DIV_2048`

      UPEVNT = QCLK/2048.

  enum `EQEP_StrobeSource`

    Values that can be passed to EQEP_setStrobeSource() as the strobeSrc parameter.

    Values:

    enumerator `EQEP_STROBE_FROM_GPIO` = 0

      Strobe signal comes from GPIO.

    enumerator `EQEP_STROBE_OR_ADCSOCA` = 2

      Strobe signal is OR’d with ADCSOCA.

    enumerator `EQEP_STROBE_OR_ADCSOCB` = 3

      Strobe signal is OR’d with ADCSOCB.

  enum `EQEP_QMAMode`

    Values that can be passed to EQEP_setQMAModuleMode() as the qmaMode parameter.

    Values:

    enumerator `EQEP_QMA_MODE_BYPASS`

      QMA module is bypassed.

    enumerator `EQEP_QMA_MODE_1`

      QMA mode-1 operation is selected.

    enumerator `EQEP_QMA_MODE_2`

      QMA mode-2 operation is selected.

  enum `EQEP_EmulationMode`

    Values that can be passed to EQEP_setEmulationMode() as the emuMode parameter.

    Values:

    enumerator `EQEP_EMULATIONMODE_STOPIMMEDIATELY`

      Counters stop immediately.

    enumerator `EQEP_EMULATIONMODE_STOPATROLLOVER`

      Counters stop at period rollover.

    enumerator `EQEP_EMULATIONMODE_RUNFREE`

      Counter unaffected by suspend.

  Functions

  void `EQEP_enableModule`(uint32_t base)

    Enables the eQEP module.

    This function enables operation of the enhanced quadrature encoder pulse (eQEP) module. The module must be configured before it is enabled.

    Parameters

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

    See

      EQEP_setConfig()

    Return

      None.

  void `EQEP_disableModule`(uint32_t base)

    Disables the eQEP module.

    This function disables operation of the eQEP module.

    Parameters

      - `base`: is the base address of the enhanced quadrature encoder pulse (eQEP) module

    Return

      None.

  void `EQEP_setDecoderConfig`(uint32_t base, uint16_t config)

    Configures eQEP module’s quadrature decoder unit.

    This function configures the operation of the eQEP module’s quadrature decoder unit. The

    config parameter provides the configuration of the decoder and is the logical OR of several values:
    Parameters

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

      - `config`: is the configuration for the eQEP module decoder unit.

    - EQEP_CONFIG_2X_RESOLUTION or EQEP_CONFIG_1X_RESOLUTION specify if both rising and falling edges should be counted or just rising edges.

    - EQEP_CONFIG_QUADRATURE, EQEP_CONFIG_CLOCK_DIR, EQEP_CONFIG_UP_COUNT, or EQEP_CONFIG_DOWN_COUNT specify if quadrature signals are being provided on QEPA and QEPB, if a direction signal and a clock are being provided, or if the direction should be hard-wired for a single direction with QEPA used for input.

    - EQEP_CONFIG_NO_SWAP or EQEP_CONFIG_SWAP to specify if the signals provided on QEPA and QEPB should be swapped before being processed.

    - EQEP_CONFIG_IGATE_DISABLE or EQEP_CONFIG_IGATE_ENABLE to specify if the gating of the index pulse should be enabled or disabled

    Return

      None.

  void `EQEP_setPositionCounterConfig`(uint32_t base, EQEP_PositionResetMode mode, uint32_t maxPosition)

    Configures eQEP module position counter unit.

    This function configures the operation of the eQEP module position counter. The

    mode parameter determines the event on which the position counter gets reset. It should be passed one of the following values: EQEP_POSITION_RESET_IDX, EQEP_POSITION_RESET_MAX_POS, EQEP_POSITION_RESET_1ST_IDX, or EQEP_POSITION_RESET_UNIT_TIME_OUT.
    Parameters

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

      - `mode`: is the configuration for the eQEP module position counter.

      - `maxPosition`: specifies the maximum position value.

    maxPosition is the maximum value of the position counter and is the value used to reset the position capture when moving in the reverse (negative) direction.

    Return

      None.

  uint32_t `EQEP_getPosition`(uint32_t base)

    Gets the current encoder position.

    This function returns the current position of the encoder. Depending upon the configuration of the encoder, and the incident of an index pulse, this value may or may not contain the expected data (that is, if in reset on index mode, if an index pulse has not been encountered, the position counter is not yet aligned with the index pulse).

    Parameters

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

    Return

      The current position of the encoder.

  void `EQEP_setPosition`(uint32_t base, uint32_t position)

    Sets the current encoder position.

    This function sets the current position of the encoder; the encoder position is then measured relative to this value.

    Parameters

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

      - `position`: is the new position for the encoder.

    Return

      None.

  int16_t `EQEP_getDirection`(uint32_t base)

    Gets the current direction of rotation.

    This function returns the current direction of rotation. In this case, current means the most recently detected direction of the encoder; it may not be presently moving but this is the direction it last moved before it stopped.

    Parameters

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

    Return

      Returns 1 if moving in the forward direction or -1 if moving in the reverse direction.

  void `EQEP_enableInterrupt`(uint32_t base, uint16_t intFlags)

    Enables individual eQEP module interrupt sources.

    This function enables eQEP module interrupt sources. The

    intFlags parameter can be any of the following values OR’d together:

    - EQEP_INT_POS_CNT_ERROR - Position counter error

    - EQEP_INT_PHASE_ERROR - Quadrature phase error

    - EQEP_INT_DIR_CHANGE - Quadrature direction change

    - EQEP_INT_WATCHDOG - Watchdog time-out

    - EQEP_INT_UNDERFLOW - Position counter underflow

    - EQEP_INT_OVERFLOW - Position counter overflow

    - EQEP_INT_POS_COMP_READY - Position-compare ready

    - EQEP_INT_POS_COMP_MATCH - Position-compare match

    - EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch

    - EQEP_INT_INDEX_EVNT_LATCH - Index event latch

    - EQEP_INT_UNIT_TIME_OUT - Unit time-out

    - EQEP_INT_QMA_ERROR - QMA error

    Parameters

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

      - `intFlags`: is a bit mask of the interrupt sources to be enabled.

    Return

      None.

  void `EQEP_disableInterrupt`(uint32_t base, uint16_t intFlags)

    Disables individual eQEP module interrupt sources.

    This function disables eQEP module interrupt sources. The

    intFlags parameter can be any of the following values OR’d together:

    - EQEP_INT_POS_CNT_ERROR - Position counter error

    - EQEP_INT_PHASE_ERROR - Quadrature phase error

    - EQEP_INT_DIR_CHANGE - Quadrature direction change

    - EQEP_INT_WATCHDOG - Watchdog time-out

    - EQEP_INT_UNDERFLOW - Position counter underflow

    - EQEP_INT_OVERFLOW - Position counter overflow

    - EQEP_INT_POS_COMP_READY - Position-compare ready

    - EQEP_INT_POS_COMP_MATCH - Position-compare match

    - EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch

    - EQEP_INT_INDEX_EVNT_LATCH - Index event latch

    - EQEP_INT_UNIT_TIME_OUT - Unit time-out

    - EQEP_INT_QMA_ERROR - QMA error

    Parameters

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

      - `intFlags`: is a bit mask of the interrupt sources to be disabled.

    Return

      None.

  uint16_t `EQEP_getInterruptStatus`(uint32_t base)

    Gets the current interrupt status.

    This function returns the interrupt status for the eQEP module module.

    Parameters

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

    Return

      Returns the current interrupt status, enumerated as a bit field of the following values:

      - EQEP_INT_GLOBAL - Global interrupt flag

      - EQEP_INT_POS_CNT_ERROR - Position counter error

      - EQEP_INT_PHASE_ERROR - Quadrature phase error

      - EQEP_INT_DIR_CHANGE - Quadrature direction change

      - EQEP_INT_WATCHDOG - Watchdog time-out

      - EQEP_INT_UNDERFLOW - Position counter underflow

      - EQEP_INT_OVERFLOW - Position counter overflow

      - EQEP_INT_POS_COMP_READY - Position-compare ready

      - EQEP_INT_POS_COMP_MATCH - Position-compare match

      - EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch

      - EQEP_INT_INDEX_EVNT_LATCH - Index event latch

      - EQEP_INT_UNIT_TIME_OUT - Unit time-out

      - EQEP_INT_QMA_ERROR - QMA error

  void `EQEP_clearInterruptStatus`(uint32_t base, uint16_t intFlags)

    Clears eQEP module interrupt sources.

    This function clears eQEP module interrupt flags. The

    intFlags parameter can be any of the following values OR’d together:

    - EQEP_INT_GLOBAL - Global interrupt flag

    - EQEP_INT_POS_CNT_ERROR - Position counter error

    - EQEP_INT_PHASE_ERROR - Quadrature phase error

    - EQEP_INT_DIR_CHANGE - Quadrature direction change

    - EQEP_INT_WATCHDOG - Watchdog time-out

    - EQEP_INT_UNDERFLOW - Position counter underflow

    - EQEP_INT_OVERFLOW - Position counter overflow

    - EQEP_INT_POS_COMP_READY - Position-compare ready

    - EQEP_INT_POS_COMP_MATCH - Position-compare match

    - EQEP_INT_STROBE_EVNT_LATCH - Strobe event latch

    - EQEP_INT_INDEX_EVNT_LATCH - Index event latch

    - EQEP_INT_UNIT_TIME_OUT - Unit time-out

    - EQEP_INT_QMA_ERROR - QMA error

    Parameters

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

      - `intFlags`: is a bit mask of the interrupt sources to be cleared.

    Note that the EQEP_INT_GLOBAL value is the global interrupt flag. In order to get any further eQEP interrupts, this flag must be cleared.

    Return

      None.

  void `EQEP_forceInterrupt`(uint32_t base, uint16_t intFlags)

    Forces individual eQEP module interrupts.

    This function forces eQEP module interrupt flags. The

    intFlags parameter can be any of the following values OR’d together:

    - EQEP_INT_POS_CNT_ERROR

    - EQEP_INT_PHASE_ERROR

    - EQEP_INT_DIR_CHANGE

    - EQEP_INT_WATCHDOG

    - EQEP_INT_UNDERFLOW

    - EQEP_INT_OVERFLOW

    - EQEP_INT_POS_COMP_READY

    - EQEP_INT_POS_COMP_MATCH

    - EQEP_INT_STROBE_EVNT_LATCH

    - EQEP_INT_INDEX_EVNT_LATCH

    - EQEP_INT_UNIT_TIME_OUT

    - EQEP_INT_QMA_ERROR

    Parameters

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

      - `intFlags`: is a bit mask of the interrupt sources to be forced.

    Return

      None.

  bool `EQEP_getError`(uint32_t base)

    Gets the encoder error indicator.

    This function returns the error indicator for the eQEP module. It is an error for both of the signals of the quadrature input to change at the same time.

    Parameters

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

    Return

      Returns true if an error has occurred and false otherwise.

  uint16_t `EQEP_getStatus`(uint32_t base)

    Returns content of the eQEP module status register

    This function returns the contents of the status register. The value it returns is an OR of the following values:

    Parameters

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

    - EQEP_STS_UNIT_POS_EVNT - Unit position event detected

    - EQEP_STS_DIR_ON_1ST_IDX - If set, clockwise rotation (forward movement) occurred on the first index event

    - EQEP_STS_DIR_FLAG - If set, movement is clockwise rotation

    - EQEP_STS_DIR_LATCH - If set, clockwise rotation occurred on last index event marker

    - EQEP_STS_CAP_OVRFLW_ERROR - Overflow occurred in eQEP capture timer

    - EQEP_STS_CAP_DIR_ERROR - Direction change occurred between position capture events

    - EQEP_STS_1ST_IDX_FLAG - Set by the occurrence of the first index pulse

    - EQEP_STS_POS_CNT_ERROR - Position counter error occurred

    Return

      Returns the value of the QEP status register.

  void `EQEP_clearStatus`(uint32_t base, uint16_t statusFlags)

    Clears selected fields of the eQEP module status register

    This function clears the status register fields indicated by

    statusFlags. The statusFlags parameter is the logical OR of any of the following:
    Parameters

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

      - `statusFlags`: is the bit mask of the status flags to be cleared.

    - EQEP_STS_UNIT_POS_EVNT - Unit position event detected

    - EQEP_STS_CAP_OVRFLW_ERROR - Overflow occurred in eQEP capture timer

    - EQEP_STS_CAP_DIR_ERROR - Direction change occurred between position capture events

    - EQEP_STS_1ST_IDX_FLAG - Set by the occurrence of the first index pulse

    Note

      Only the above status fields can be cleared. All others are read-only, non-sticky fields.

    Return

      None.

  void `EQEP_setCaptureConfig`(uint32_t base, EQEP_CAPCLKPrescale capPrescale, EQEP_UPEVNTPrescale evntPrescale)

    Configures eQEP module edge-capture unit.

    This function configures the operation of the eQEP module edge-capture unit. The

    capPrescale parameter provides the configuration of the eQEP capture timer clock rate. It determines by which power of 2 between 1 and 128 inclusive SYSCLKOUT is divided. The macros for this parameter are in the format of EQEP_CAPTURE_CLK_DIV_X, where X is the divide value. For example, EQEP_CAPTURE_CLK_DIV_32 will give a capture timer clock frequency that is SYSCLKOUT/32.
    Parameters

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

      - `capPrescale`: is the prescaler setting of the eQEP capture timer clk.

      - `evntPrescale`: is the prescaler setting of the unit position event frequency.

    The evntPrescale parameter determines how frequently a unit position event occurs. The macro that can be passed this parameter is in the format EQEP_UNIT_POS_EVNT_DIV_X, where X is the number of quadrature clock periods between unit position events. For example, EQEP_UNIT_POS_EVNT_DIV_16 will result in a unit position event frequency of QCLK/16.

    Return

      None.

  void `EQEP_enableCapture`(uint32_t base)

    Enables the eQEP module edge-capture unit.

    This function enables operation of the eQEP module’s edge-capture unit.

    Parameters

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

    Return

      None.

  void `EQEP_disableCapture`(uint32_t base)

    Disables the eQEP module edge-capture unit.

    This function disables operation of the eQEP module’s edge-capture unit.

    Parameters

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

    Return

      None.

  uint16_t `EQEP_getCapturePeriod`(uint32_t base)

    Gets the encoder capture period.

    This function returns the period count value between the last successive eQEP position events.

    Parameters

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

    Return

      The period count value between the last successive position events.

  uint16_t `EQEP_getCaptureTimer`(uint32_t base)

    Gets the encoder capture timer value.

    This function returns the time base for the edge capture unit.

    Parameters

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

    Return

      The capture timer value.

  void `EQEP_enableCompare`(uint32_t base)

    Enables the eQEP module position-compare unit.

    This function enables operation of the eQEP module’s position-compare unit.

    Parameters

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

    Return

      None.

  void `EQEP_disableCompare`(uint32_t base)

    Disables the eQEP module position-compare unit.

    This function disables operation of the eQEP module’s position-compare unit.

    Parameters

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

    Return

      None.

  void `EQEP_setComparePulseWidth`(uint32_t base, uint16_t cycles)

    Configures the position-compare unit’s sync output pulse width.

    This function configures the width of the sync output pulse. The width of the pulse will be

    cycles * 4 * the width of a SYSCLKOUT cycle. The maximum width is 4096 * 4 * SYSCLKOUT cycles.
    Parameters

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

      - `cycles`: is the width of the pulse that can be generated on a position-compare event. It is in units of 4 SYSCLKOUT cycles.

    Return

      None.

  void `EQEP_loadUnitTimer`(uint32_t base, uint32_t period)

    Loads the eQEP module unit timer period as number of SYSCLK cycles.

    This function sets the unit time-out interrupt when it matches the value specified by

    period The unit timer is clocked by SYSCLKOUT
    Parameters

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

      - `period`: is period value at which a unit time-out interrupt is set.

    Return

      None.

  void `EQEP_enableUnitTimer`(uint32_t base, uint32_t period)

    Enables the eQEP module unit timer.

    This function enables operation of the eQEP module’s peripheral unit timer. The unit timer is clocked by SYSCLKOUT and will set the unit time-out interrupt when it matches the value specified by

    period.
    Parameters

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

      - `period`: is period value at which a unit time-out interrupt is set.

    Return

      None.

  void `EQEP_disableUnitTimer`(uint32_t base)

    Disables the eQEP module unit timer.

    This function disables operation of the eQEP module’s peripheral unit timer.

    Parameters

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

    Return

      None.

  void `EQEP_enableWatchdog`(uint32_t base, uint16_t period)

    Enables the eQEP module watchdog timer.

    This function enables operation of the eQEP module’s peripheral watchdog timer.

    Parameters

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

      - `period`: is watchdog period value at which a time-out will occur if no quadrature-clock event is detected.

    Note

      When selecting period, note that the watchdog timer is clocked from SYSCLKOUT/64.

    Return

      None.

  void `EQEP_disableWatchdog`(uint32_t base)

    Disables the eQEP module watchdog timer.

    This function disables operation of the eQEP module’s peripheral watchdog timer.

    Parameters

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

    Return

      None.

  void `EQEP_setWatchdogTimerValue`(uint32_t base, uint16_t value)

    Sets the eQEP module watchdog timer value.

    This function sets the eQEP module’s watchdog timer value.

    Parameters

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

      - `value`: is the value to be written to the watchdog timer.

    Return

      None.

  uint16_t `EQEP_getWatchdogTimerValue`(uint32_t base)

    Gets the eQEP module watchdog timer value.

    Return

      Returns the current watchdog timer value.

    Parameters

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

  void `EQEP_setPositionInitMode`(uint32_t base, uint16_t initMode)

    Configures the mode in which the position counter is initialized.

    This function configures the events on which the position count can be initialized. The

    initMode parameter provides the mode as either EQEP_INIT_DO_NOTHING (no action configured) or one of the following strobe events, index events, or a logical OR of both a strobe event and an index event.
    Parameters

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

      - `initMode`: is the configuration for initializing the position count. See below for a description of this parameter.

    - EQEP_INIT_RISING_STROBE or EQEP_INIT_EDGE_DIR_STROBE specify which strobe event will initialize the position counter.

    - EQEP_INIT_RISING_INDEX or EQEP_INIT_FALLING_INDEX specify which index event will initialize the position counter.

    Use EQEP_setSWPositionInit() to cause a software initialization and EQEP_setInitialPosition() to set the value that gets loaded into the position counter upon initialization.

    Return

      None.

  void `EQEP_setSWPositionInit`(uint32_t base, bool initialize)

    Sets the software initialization of the encoder position counter.

    This function does a software initialization of the position counter when the

    initialize parameter is true. When false, the QEPCTL[SWI] bit is cleared and no action is taken.
    Parameters

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

      - `initialize`: is a flag to specify if software initialization of the position counter is enabled.

    The init value to be loaded into the position counter can be set with EQEP_setInitialPosition(). Additional initialization causes can be configured with EQEP_setPositionInitMode().

    Return

      None.

  void `EQEP_setInitialPosition`(uint32_t base, uint32_t position)

    Sets the init value for the encoder position counter.

    This function sets the init value for position of the encoder. See

    EQEP_setPositionInitMode() to set the initialization cause or EQEP_setSWPositionInit() to cause a software initialization.
    Parameters

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

      - `position`: is the value to be written to the position counter upon. initialization.

    Return

      None.

  void `EQEP_setLatchMode`(uint32_t base, uint32_t latchMode)

    Configures the quadrature modes in which the position count can be latched.

    This function configures the events on which the position count and several other registers can be latched. The

    latchMode parameter provides the mode as the logical OR of several values.
    Parameters

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

      - `latchMode`: is the configuration for latching of the position count and several other registers. See below for a description of this parameter.

    - EQEP_LATCH_CNT_READ_BY_CPU or EQEP_LATCH_UNIT_TIME_OUT specify the event that latches the position counter. This latch register can be read using EQEP_getPositionLatch(). The capture timer and capture period are also latched based on this setting, and can be read using EQEP_getCaptureTimerLatch() and EQEP_getCapturePeriodLatch().

    - EQEP_LATCH_RISING_STROBE or EQEP_LATCH_EDGE_DIR_STROBE specify which strobe event will latch the position counter into the strobe position latch register. This register can be read with EQEP_getStrobePositionLatch().

    - EQEP_LATCH_RISING_INDEX, EQEP_LATCH_FALLING_INDEX, or EQEP_LATCH_SW_INDEX_MARKER specify which index event will latch the position counter into the index position latch register. This register can be read with EQEP_getIndexPositionLatch().

    Return

      None.

  uint32_t `EQEP_getIndexPositionLatch`(uint32_t base)

    Gets the encoder position that was latched on an index event.

    This function returns the value in the index position latch register. The position counter is latched into this register on either a rising index edge, a falling index edge, or a software index marker. This is configured using

    EQEP_setLatchMode().
    Parameters

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

    Return

      The position count latched on an index event.

  uint32_t `EQEP_getStrobePositionLatch`(uint32_t base)

    Gets the encoder position that was latched on a strobe event.

    This function returns the value in the strobe position latch register. The position counter can be configured to be latched into this register on rising strobe edges only or on rising strobe edges while moving clockwise and falling strobe edges while moving counter-clockwise. This is configured using

    EQEP_setLatchMode().
    Parameters

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

    Return

      The position count latched on a strobe event.

  uint32_t `EQEP_getPositionLatch`(uint32_t base)

    Gets the encoder position that was latched on a unit time-out event.

    This function returns the value in the position latch register. The position counter is latched into this register either on a unit time-out event.

    Parameters

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

    Return

      The position count latch register value.

  uint16_t `EQEP_getCaptureTimerLatch`(uint32_t base)

    Gets the encoder capture timer latch.

    This function returns the value in the capture timer latch register. The capture timer value is latched into this register either on a unit time-out event or upon the CPU reading the eQEP position counter. This is configured using

    EQEP_setLatchMode().
    Parameters

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

    Return

      The edge-capture timer latch value.

  uint16_t `EQEP_getCapturePeriodLatch`(uint32_t base)

    Gets the encoder capture period latch.

    This function returns the value in the capture period latch register. The capture period value is latched into this register either on a unit time-out event or upon the CPU reading the eQEP position counter. This is configured using

    EQEP_setLatchMode().
    Parameters

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

    Return

      The edge-capture period latch value.

  void `EQEP_setQMAModuleMode`(uint32_t base, EQEP_QMAMode qmaMode)

    Set the quadrature mode adapter (QMA) module mode

    This function sets the quadrature mode adapter module mode. The possible modes are passed to the function through the

    qmaMode parameter which can take the values EQEP_QMA_MODE_BYPASS, EQEP_QMA_MODE_1, or EQEP_QMA_MODE_2.
    Parameters

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

      - `qmaMode`: is the mode in which the QMA module will operate.

    To use the QMA module, you must first put the eQEP module into direction-count mode (EQEP_CONFIG_CLOCK_DIR) using EQEP_setConfig().

    Return

      None.

  void `EQEP_setStrobeSource`(uint32_t base, EQEP_StrobeSource strobeSrc)

    Set the strobe input source of the eQEP module.

    This function sets the source of the eQEP module’s strobe signal. The possible values of the

    strobeSrc parameter are

    - EQEP_STROBE_FROM_GPIO - The strobe is used as-is after passing through the polarity select logic.

    - EQEP_STROBE_OR_ADCSOCA - The strobe is OR’d with the ADCSOCA signal after passing through the polarity select logic.

    - EQEP_STROBE_OR_ADCSOCB - The strobe is OR’d with the ADCSOCB signal after passing through the polarity select logic.

    Parameters

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

      - `strobeSrc`: is the source of the strobe signal.

    Return

      None.

  void `EQEP_setEmulationMode`(uint32_t base, EQEP_EmulationMode emuMode)

    Set the emulation mode of the eQEP module.

    This function sets the eQEP module’s emulation mode. This mode determines how the timers are affected by an emulation suspend. Valid values for the

    emuMode parameter are the following:
    Parameters

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

      - `emuMode`: is the mode operation upon an emulation suspend.

    - EQEP_EMULATIONMODE_STOPIMMEDIATELY - The position counter, watchdog counter, unit timer, and capture timer all stop immediately.

    - EQEP_EMULATIONMODE_STOPATROLLOVER - The position counter, watchdog counter, unit timer all count until period rollover. The capture timer counts until the next unit period event.

    - EQEP_EMULATIONMODE_RUNFREE - The position counter, watchdog counter, unit timer, and capture timer are all unaffected by an emulation suspend.

    Return

      None.

  void `EQEP_setCompareConfig`(uint32_t base, uint16_t config, uint32_t compareValue, uint16_t cycles)

    Configures eQEP module position-compare unit.

    This function configures the operation of the eQEP module position-compare unit. The

    config parameter provides the configuration of the position-compare unit and is the logical OR of several values:
    Parameters

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

      - `config`: is the configuration for the eQEP module position-compare unit. See below for a description of this parameter.

      - `compareValue`: is the value to which the position count value is compared for a position-compare event.

      - `cycles`: is the width of the pulse that can be generated on a position-compare event. It is in units of 4 SYSCLKOUT cycles.

    - EQEP_COMPARE_NO_SYNC_OUT, EQEP_COMPARE_IDX_SYNC_OUT, or EQEP_COMPARE_STROBE_SYNC_OUT specify if there is a sync output pulse and which pin should be used.

    - EQEP_COMPARE_NO_SHADOW, EQEP_COMPARE_LOAD_ON_ZERO, or EQEP_COMPARE_LOAD_ON_MATCH specify if a shadow is enabled and when should the load should occurQPOSCNT = 0 or QPOSCNT = QPOSCOMP.

    The cycles is used to select the width of the sync output pulse. The width of the resulting pulse will be cycles * 4 * the width of a SYSCLKOUT cycle. The maximum width is 4096 * 4 * SYSCLKOUT cycles.

    Note

      You can set the sync pulse width independently using the EQEP_setComparePulseWidth() function.

    Return

      None.

  void `EQEP_setInputPolarity`(uint32_t base, bool invertQEPA, bool invertQEPB, bool invertIndex, bool invertStrobe)

    Sets the polarity of the eQEP module’s input signals.

    This function configures the polarity of the inputs to the eQEP module. To negate the polarity of any of the input signals, pass

    true into its corresponding parameter in this function. Pass false to leave it as-is.
    Parameters

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

      - `invertQEPA`: is the flag to negate the QEPA input.

      - `invertQEPB`: is the flag to negate the QEPA input.

      - `invertIndex`: is the flag to negate the index input.

      - `invertStrobe`: is the flag to negate the strobe input.

    Return

      None.

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