Modbus-rtu/PLSR/Src/plsr.c

#include "plsr.h"
#include "plsr_internal.h"
#include "plsr_planner.h"
#include "plsr_platform.h"
#include <stddef.h>
#include <string.h>

#if defined(__ICCARM__)
#include <intrinsics.h>
#endif

#define PLSR_COMMON_FIRST_ADDRESS      (0x1000U)
#define PLSR_COMMON_LAST_ADDRESS       (0x10FFU)
#define PLSR_SEGMENT_FIRST_ADDRESS     (0x1100U)
#define PLSR_SEGMENT_STRIDE            (0x0010U)
#define PLSR_SEGMENT_DEFINED_WORDS     (8U)

#define PLSR_WAIT_TIME                 (0U)
#define PLSR_WAIT_SIGNAL               (1U)
#define PLSR_ACT_TIME                  (2U)
#define PLSR_EXT_SIGNAL                (3U)
#define PLSR_EXT_OR_COMPLETE           (4U)

#define PLSR_SEND_COMPLETE             (0U)
#define PLSR_SEND_SUBSEQUENT           (1U)
#define PLSR_POSITION_RELATIVE         (0U)
#define PLSR_POSITION_ABSOLUTE         (1U)

#define PLSR_COMMAND_START             (0x0001U)
#define PLSR_COMMAND_STOP              (0x0002U)
#define PLSR_COMMAND_CLEAR             (0x0004U)

#define PLSR_DIAG_FLAG_MONITORING       (0x0001U)
#define PLSR_DIAG_FLAG_COUNT_CHECKED    (0x0002U)
#define PLSR_DIAG_FLAG_COUNT_PASS       (0x0004U)
#define PLSR_DIAG_FLAG_FREQUENCY_CHECKED (0x0008U)
#define PLSR_DIAG_FLAG_FREQUENCY_PASS   (0x0010U)
#define PLSR_DIAG_FLAG_CURVE_CHECKED    (0x0020U)
#define PLSR_DIAG_FLAG_CURVE_PASS       (0x0040U)
#define PLSR_DIAG_FLAG_FAULT_LATCHED    (0x0080U)

#define PLSR_DIAG_REASON_NONE           (0U)
#define PLSR_DIAG_REASON_COUNT          (1U)
#define PLSR_DIAG_REASON_FREQUENCY      (2U)
#define PLSR_DIAG_REASON_CURVE          (3U)
#define PLSR_DIAG_REASON_INVALID_SAMPLE (4U)

#define PLSR_CONFIG_SAVE_DELAY_MS      (1000U)
#define PLSR_POSITION_CHECKPOINT_MS    (10U)
#define PLSR_PROFILE_QUEUE_CAPACITY    (1024U)
#define PLSR_PROFILE_QUEUE_MASK        (PLSR_PROFILE_QUEUE_CAPACITY - 1U)
#define PLSR_HANDOFF_WARMUP_ITEMS      (8U)
#define PLSR_REPLAN_WARMUP_ITEMS       (8U)
#define PLSR_RAMP_POLL_RESERVE_AREA_DIVISOR (20ULL)

typedef struct
{
    uint32_t fromHz;
    uint32_t toHz;
    uint32_t durationMs;
    uint32_t elapsedMs;
    uint8_t active;
} PLSR_RAMP;

typedef struct
{
    PLSR_PLANNER_CONTEXT planner;
    PLSR_STREAM_ITEM pendingItem;
    uint32_t startHz;
    uint32_t peakHz;
    uint32_t endHz;
    uint32_t pulseCount;
    uint32_t entryPulses;
    uint32_t steadyPulses;
    uint32_t exitPulses;
    volatile uint32_t nextPeriod;
    uint32_t pendingRepeats;
    uint32_t lastRampFrequencyHz;
    volatile uint8_t active;
} PLSR_SHORT_PROFILE;

typedef struct
{
    PLSR_PLATFORM_TIMER_SETTING setting;
    uint32_t requestedFrequencyHz;
} PLSR_PROFILE_ENTRY;

typedef struct
{
    PLSR_PROFILE_ENTRY entries[PLSR_PROFILE_QUEUE_CAPACITY];
    PLSR_SHORT_PROFILE producerProfile;
    volatile uint32_t readIndex;
    volatile uint32_t writeIndex;
    volatile uint32_t generation;
    uint32_t producerEpoch;
    uint8_t producerSegment;
    uint8_t preparedHandoffBank;
    volatile uint8_t active;
    volatile uint8_t generatorComplete;
} PLSR_PROFILE_QUEUE;

typedef struct
{
    uint64_t magnitude;
    uint32_t firstFrequencyHz;
    uint32_t secondFrequencyHz;
    uint32_t firstRequestedFrequencyHz;
    uint32_t secondRequestedFrequencyHz;
    PLSR_PLATFORM_TIMER_SETTING firstSetting;
    PLSR_PLATFORM_TIMER_SETTING secondSetting;
    PLSR_PROFILE_ENTRY warmup[PLSR_HANDOFF_WARMUP_ITEMS];
    PLSR_SHORT_PROFILE profile;
    uint8_t warmupCount;
    uint8_t nextSegment;
    uint8_t positive;
    volatile uint8_t valid;
} PLSR_HANDOFF_PLAN;

typedef enum
{
    PLSR_WORD_OK = 0,
    PLSR_WORD_ILLEGAL_ADDRESS,
    PLSR_WORD_ILLEGAL_VALUE
} PLSR_WORD_RESULT;

typedef enum
{
    PLSR_COMMAND_MAILBOX_EMPTY = 0,
    PLSR_COMMAND_MAILBOX_PENDING,
    PLSR_COMMAND_MAILBOX_EXECUTING
} PLSR_COMMAND_MAILBOX_STATE;

typedef struct
{
    PLSR_CONFIG startConfig;
    uint16_t command;
    volatile uint8_t state;
} PLSR_COMMAND_MAILBOX;

typedef struct
{
    volatile PLSR_EXEC_MODE mode;
    volatile uint32_t generation;
} PLSR_EXECUTOR;

typedef struct
{
    uint16_t flags;
    uint16_t reason;
    uint16_t lastSegment;
    uint16_t modeDirection;
    uint32_t expectedCycles;
    uint32_t observedCycles;
    int32_t countError;
    uint32_t requestedHz;
    uint32_t expectedTimerHz;
    uint32_t activeTimerHz;
    int32_t requestErrorHz;
    uint32_t curveSampleCount;
    uint32_t curveMismatchCount;
    uint32_t curveMaxAbsErrorHz;
    uint32_t firstMismatchSample;
} PLSR_DIAGNOSTIC;

static const uint16_t PlsrSineProgressQ16[65] =
{
    0U, 39U, 158U, 355U, 630U, 982U, 1411U, 1915U,
    2494U, 3146U, 3869U, 4662U, 5522U, 6448U, 7438U, 8488U,
    9597U, 10762U, 11980U, 13248U, 14563U, 15922U, 17321U,
    18758U, 20228U, 21728U, 23256U, 24806U, 26375U, 27960U,
    29556U, 31160U, 32767U, 34375U, 35979U, 37575U, 39160U,
    40729U, 42279U, 43807U, 45307U, 46777U, 48214U, 49613U,
    50972U, 52287U, 53555U, 54773U, 55938U, 57047U, 58097U,
    59087U, 60013U, 60873U, 61666U, 62389U, 63041U, 63620U,
    64124U, 64553U, 64905U, 65180U, 65377U, 65496U, 65535U
};

static PLSR_CONFIG PlsrShadowConfig;
static PLSR_CONFIG PlsrActiveConfig;
static PLSR_CONFIG PlsrCandidateConfig;
static volatile int32_t PlsrPosition;
static volatile uint64_t PlsrRemainingPulses;
static volatile uint8_t PlsrPulseActive;
static volatile uint8_t PlsrCutRequested;
static volatile uint8_t PlsrBoundaryPending;
static volatile uint8_t PlsrBoundaryWasCut;
static volatile uint8_t PlsrCountPositive;
static volatile uint8_t PlsrCountOverflowPending;
static volatile uint8_t PlsrPositionValid;
static volatile uint8_t PlsrPositionCheckpointDirty;
static volatile uint8_t PlsrFrequencyUpdatePending;
static volatile uint8_t PlsrFrequencyUpdateSegment;
static volatile uint8_t PlsrSeamlessHandoffPending;
static volatile uint8_t PlsrTimerErrorPending;
static volatile uint8_t PlsrDeferredFrequencyPending;
static volatile uint32_t PlsrCurrentFrequencyHz;
static volatile uint32_t PlsrQueuedFrequencyHz;
static volatile uint32_t PlsrBoundaryFrequencyHz;
static volatile uint32_t PlsrFrequencyUpdateTargetHz;
static volatile uint32_t PlsrDeferredFrequencyHz;
static volatile uint32_t PlsrSegmentEpoch;

static volatile PLSR_STATUS PlsrRunStatus = PLSR_STATUS_UNINITIALIZED;
static PLSR_ERROR PlsrError = PLSR_ERROR_NONE;
static PLSR_RAMP PlsrRamp;
static PLSR_SHORT_PROFILE PlsrShortProfile;
static PLSR_PROFILE_QUEUE PlsrProfileQueue;
static PLSR_HANDOFF_PLAN PlsrHandoffPlan;
static PLSR_HANDOFF_PLAN
    PlsrPreparedHandoffPlans[2][PLSR_SEGMENT_COUNT_MAX];
static volatile uint8_t PlsrPreparedHandoffBank;
#ifdef PLSR_HOST_TEST
static uint32_t PlsrHostTestEventSequence;
static uint32_t PlsrHostTestLastGateEvent;
static uint32_t PlsrHostTestLastDiagnosticFinishEvent;
#endif
static uint8_t PlsrInitialized;
static volatile uint8_t PlsrCurrentSegment;
static uint8_t PlsrDirectionDelayActive;
static uint16_t PlsrDirectionDelayRemainingMs;
static volatile uint8_t PlsrSegmentClockStarted;
static volatile uint32_t PlsrSegmentElapsedMs;
static volatile uint32_t PlsrWaitElapsedMs;
static volatile uint8_t PlsrExtPreviousLevel;
static volatile uint8_t PlsrExtEdgePending;
static volatile uint8_t PlsrStopRequested;
static volatile uint8_t PlsrStopPulsesRemaining;
static volatile uint8_t PlsrAbStopArmed;
static volatile uint8_t PlsrBoundaryRampStarted;
static uint8_t PlsrLastDirectionValid;
static uint8_t PlsrLastDirectionOutput;
static uint8_t PlsrLastDirectionLevel;
static uint8_t PlsrPersistenceDirty;
static uint16_t PlsrPersistenceDelayMs;
static uint8_t PlsrPositionCheckpointElapsedMs;
static PLSR_COMMAND_MAILBOX PlsrCommandMailbox;
static PLSR_EXECUTOR PlsrExecutor;
static volatile PLSR_DIAGNOSTIC PlsrDiagnostic;
static volatile uint64_t PlsrDiagnosticSegmentCounterBase;
static volatile uint32_t PlsrDiagnosticQueuedExpectedHz;
static volatile uint16_t PlsrDiagnosticFailedChecks;

#if defined(PLSR_DEBUG_TIMING) && (PLSR_DEBUG_TIMING != 0)
volatile uint32_t PlsrProfileProducerItemCount;
volatile uint32_t PlsrProfileProducerTotalCycles;
volatile uint32_t PlsrProfileProducerMaxItemCycles;
#endif

static uint8_t PlsrIsBusy(void);
static void PlsrSetDefaults(PLSR_CONFIG *config);
static uint8_t PlsrConfigIsValid(const PLSR_CONFIG *config,
                                 uint8_t validateActivePath);
static uint32_t PlsrResolvedSegmentFrequency(const PLSR_CONFIG *config,
                                             uint8_t segmentIndex);
static uint16_t PlsrReadConfigWord(const PLSR_CONFIG *config,
                                   uint16_t address);
static PLSR_WORD_RESULT PlsrWriteConfigWord(PLSR_CONFIG *config,
                                            uint16_t address,
                                            uint16_t value);
static uint8_t PlsrAddressIsDwordHalf(uint16_t address,
                                      uint16_t *pairedAddress);
static PLSR_MB_RESULT PlsrQueueCommand(uint16_t command);
static uint8_t PlsrPollCommandMailbox(void);
static void PlsrExecuteStart(void);
static uint8_t PlsrExecuteStop(void);
static void PlsrExecuteClear(void);
static uint8_t PlsrStartSegment(uint8_t segmentNumber,
                                uint8_t allowCarry,
                                uint32_t carryFrequencyHz);
static uint32_t PlsrEffectiveStartFrequency(uint32_t segmentFrequencyHz,
                                            uint8_t allowCarry,
                                            uint8_t directionChanged,
                                            uint32_t carryFrequencyHz);
static uint32_t PlsrEffectiveStopFrequency(uint32_t segmentFrequencyHz);
static uint8_t PlsrBeginSegmentOutput(uint32_t startFrequencyHz);
static void PlsrHandleBoundary(uint8_t extEdge);
static void PlsrTransitionToNext(uint8_t allowCarry);
static void PlsrFinishCompleted(void);
static void PlsrFinishStopped(void);
static void PlsrEnterError(PLSR_ERROR error);
static void PlsrEnterErrorIfEpoch(PLSR_ERROR error,
                                  uint32_t expectedEpoch);
static void PlsrMarkPersistenceDirty(uint16_t delayMs);
static void PlsrCheckpointPosition(uint8_t wasBusy);
static void PlsrPollPositionCheckpoint(void);
static PLSR_PLATFORM_QUEUE_RESULT PlsrTryContinuousHandoff(void);
static uint8_t PlsrPrepareShortProfile(PLSR_SHORT_PROFILE *profile,
                                       uint8_t segmentNumber,
                                       uint32_t startFrequencyHz,
                                       uint32_t targetFrequencyHz,
                                       uint64_t pulseCount);
static uint32_t PlsrShortProfileTakeFrequency(PLSR_SHORT_PROFILE *profile);
static uint8_t PlsrReplanPulseDir(uint32_t targetHz,
                                  uint32_t totalPulses);
static void PlsrProfileQueueReset(void);
static void PlsrProfileQueueInvalidateGeneration(void);
static uint8_t PlsrProfileQueueBegin(
    const PLSR_SHORT_PROFILE *producerProfile,
    uint32_t producerEpoch,
    uint8_t producerSegment,
    uint8_t preparedHandoffBank);
static uint8_t PlsrProfileQueueFill(uint16_t targetCount);
static PLSR_PLATFORM_QUEUE_RESULT PlsrProfileQueueCommitNext(
    uint8_t pulseOutput);
static uint8_t PlsrPrepareFutureHandoffQueue(void);
static void PlsrActivateHandoffQueueFromIrq(
    const PLSR_HANDOFF_PLAN *plan,
    uint32_t producerEpoch);
static void PlsrCopyShortProfile(PLSR_SHORT_PROFILE *destination,
                                 const PLSR_SHORT_PROFILE *source);
static void PlsrInvalidateHandoffPlans(void);
static uint8_t PlsrBuildHandoffPlanBank(
    const PLSR_CONFIG *frequencyConfig);
static uint8_t PlsrSelectPreparedHandoffPlan(PLSR_HANDOFF_PLAN *plan);
static PLSR_PLATFORM_QUEUE_RESULT PlsrPrimeHandoff(void);
static uint8_t PlsrBuildHandoffPlan(uint8_t sourceSegment,
                                    const PLSR_CONFIG *frequencyConfig,
                                    uint32_t carryFrequencyHz,
                                    PLSR_HANDOFF_PLAN *plan);
static void PlsrRefreshCurrentHandoffPlan(uint32_t terminalFrequencyHz);
static void PlsrDiagnosticReset(void);
static void PlsrDiagnosticBeginSegment(uint8_t segmentNumber,
                                       uint64_t expectedCycles,
                                       uint8_t directionPositive);
static void PlsrDiagnosticFinishSegment(uint8_t completedNormally);
static uint8_t PlsrDiagnosticStartPulse(uint8_t pulseOutput,
                                        uint32_t requestedFirstHz,
                                        uint32_t requestedQueuedHz,
                                        uint32_t *actualFirstHz,
                                        uint32_t *actualQueuedHz);
static PLSR_PLATFORM_QUEUE_RESULT PlsrDiagnosticQueueFrequency(
    uint8_t pulseOutput,
    uint32_t requestedHz,
    uint32_t *actualHz);
static void PlsrDiagnosticCheckActiveFrequency(uint32_t activeHz);
static uint8_t PlsrArmFinalAbBoundaryLocked(void);
#if defined(PLSR_DEBUG_TIMING) && (PLSR_DEBUG_TIMING != 0) \
    && !defined(PLSR_HOST_TEST)
static uint32_t PlsrProfileTimingNow(void);
#endif
static uint8_t PlsrQueueFinalAbBoundaryFromIrq(void);

static uint8_t PlsrIsBusy(void)
{
    return ((PlsrRunStatus == PLSR_STATUS_ACCELERATING)
            || (PlsrRunStatus == PLSR_STATUS_RUNNING)
            || (PlsrRunStatus == PLSR_STATUS_DECELERATING)
            || (PlsrRunStatus == PLSR_STATUS_WAITING)
            || (PlsrRunStatus == PLSR_STATUS_PAUSED)) ? 1U : 0U;
}

static uint32_t PlsrJoinU32(uint16_t lowWord, uint16_t highWord)
{
    return (uint32_t)lowWord | ((uint32_t)highWord << 16U);
}

static uint16_t PlsrLowWord(uint32_t value)
{
    return (uint16_t)(value & 0xFFFFUL);
}

static uint16_t PlsrHighWord(uint32_t value)
{
    return (uint16_t)(value >> 16U);
}

static uint8_t PlsrFinalAbBoundaryRequired(void)
{
    uint8_t finalBoundary;

    if (PlsrActiveConfig.outputMode != PLSR_OUTPUT_AB)
    {
        return 0U;
    }

    finalBoundary = ((PlsrCutRequested != 0U)
                     || ((PlsrStopRequested != 0U)
                         && (PlsrStopPulsesRemaining == 1U))
                     || ((PlsrRemainingPulses == 1UL)
                         && (PlsrHandoffPlan.valid == 0U))) ? 1U : 0U;
    return ((PlsrPulseActive != 0U) && (finalBoundary != 0U)) ? 1U : 0U;
}

static uint8_t PlsrCompleteFinalAbArmLocked(void)
{
    PLSR_PLATFORM_STOP_RESULT result;
    uint8_t pulseOutput = (uint8_t)PlsrActiveConfig.pulseOutput;

    result = PlsrPlatformRequestStopLocked(pulseOutput, 1U);
    if (result == PLSR_PLATFORM_STOP_PENDING)
    {
        PlsrQueuedFrequencyHz = PlsrCurrentFrequencyHz;
        PlsrDiagnosticQueuedExpectedHz = PlsrCurrentFrequencyHz;
        PlsrDeferredFrequencyHz = PlsrCurrentFrequencyHz;
        PlsrDeferredFrequencyPending = 0U;
        PlsrFrequencyUpdatePending = 0U;
        PlsrShortProfile.active = 0U;
        PlsrHandoffPlan.valid = 0U;
        PlsrRamp.active = 0U;
        return 1U;
    }
    PlsrTimerErrorPending = 1U;
    PlsrPlatformStopPulse(pulseOutput);
    PlsrAbStopArmed = 0U;
    PlsrPulseActive = 0U;
    PlsrBoundaryFrequencyHz = PlsrCurrentFrequencyHz;
    PlsrBoundaryWasCut = (PlsrCutRequested != 0U) ? 1U : 0U;
    PlsrCutRequested = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrBoundaryPending = 1U;
    return 0U;
}

static uint8_t PlsrArmFinalAbBoundaryLocked(void)
{
    if (PlsrFinalAbBoundaryRequired() == 0U)
    {
        return 1U;
    }
    if (PlsrAbStopArmed != 0U)
    {
        return 1U;
    }
    PlsrAbStopArmed = 1U;
    return PlsrCompleteFinalAbArmLocked();
}

static uint8_t PlsrQueueFinalAbBoundaryFromIrq(void)
{
    uint32_t criticalState;

    if ((PlsrFinalAbBoundaryRequired() == 0U)
        || (PlsrAbStopArmed != 0U))
    {
        return 1U;
    }
    PlsrAbStopArmed = 1U;
    if (PlsrPlatformQueueFinalArmFromIrq(
            (uint8_t)PlsrActiveConfig.pulseOutput) != 0U)
    {
        return 1U;
    }
    criticalState = PlsrPlatformEnterCritical();
    if ((PlsrAbStopArmed == 0U)
        || (PlsrFinalAbBoundaryRequired() == 0U))
    {
        PlsrPlatformExitCritical(criticalState);
        return 1U;
    }
    {
        uint8_t result = PlsrCompleteFinalAbArmLocked();

        PlsrPlatformExitCritical(criticalState);
        return result;
    }
}

void PlsrFinalArmJobIrq(uint8_t pulseOutput)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();

    if ((PlsrAbStopArmed == 0U) || (PlsrPulseActive == 0U)
        || (pulseOutput != (uint8_t)PlsrActiveConfig.pulseOutput)
        || (PlsrFinalAbBoundaryRequired() == 0U))
    {
        if ((PlsrPulseActive != 0U)
            && (pulseOutput == (uint8_t)PlsrActiveConfig.pulseOutput))
        {
            PlsrAbStopArmed = 0U;
        }
        PlsrPlatformExitCritical(criticalState);
        return;
    }
    (void)PlsrCompleteFinalAbArmLocked();
    PlsrPlatformExitCritical(criticalState);
}

static uint32_t PlsrAbsDifferenceU32(uint32_t first, uint32_t second)
{
    return (first >= second) ? (first - second) : (second - first);
}

static int32_t PlsrDifferenceI32(uint32_t first, uint32_t second)
{
    int64_t difference = (int64_t)first - (int64_t)second;

    if (difference > INT32_MAX)
    {
        return INT32_MAX;
    }
    if (difference < INT32_MIN)
    {
        return INT32_MIN;
    }
    return (int32_t)difference;
}

static void PlsrDiagnosticLatch(uint16_t reason)
{
    PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_FAULT_LATCHED;
    if (PlsrDiagnostic.reason == PLSR_DIAG_REASON_NONE)
    {
        PlsrDiagnostic.reason = reason;
    }
}

static void PlsrDiagnosticReset(void)
{
    (void)memset((void *)&PlsrDiagnostic, 0, sizeof(PlsrDiagnostic));
    PlsrDiagnostic.firstMismatchSample = 0xFFFFFFFFUL;
    PlsrDiagnosticSegmentCounterBase = 0UL;
    PlsrDiagnosticQueuedExpectedHz = 0UL;
    PlsrDiagnosticFailedChecks = 0U;
}

static void PlsrDiagnosticBeginSegment(uint8_t segmentNumber,
                                       uint64_t expectedCycles,
                                       uint8_t directionPositive)
{
    if (expectedCycles > 0xFFFFFFFFUL)
    {
        PlsrDiagnostic.expectedCycles = 0xFFFFFFFFUL;
        PlsrDiagnosticLatch(PLSR_DIAG_REASON_INVALID_SAMPLE);
    }
    else
    {
        PlsrDiagnostic.expectedCycles = (uint32_t)expectedCycles;
    }
    PlsrDiagnostic.flags &= (uint16_t)~(PLSR_DIAG_FLAG_COUNT_CHECKED
                                        | PLSR_DIAG_FLAG_COUNT_PASS);
    PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_MONITORING;
    PlsrDiagnostic.lastSegment = segmentNumber;
    PlsrDiagnostic.modeDirection =
        (uint16_t)(PlsrActiveConfig.outputMode
                   | ((uint16_t)directionPositive << 8U));
    PlsrDiagnostic.observedCycles = 0UL;
    PlsrDiagnostic.countError = 0L;
    PlsrDiagnosticSegmentCounterBase = PlsrPlatformObservedPulses(
        (uint8_t)PlsrActiveConfig.pulseOutput);
}

static void PlsrDiagnosticFinishSegment(uint8_t completedNormally)
{
    uint64_t now;
    uint64_t observed;
    uint32_t observedCycles;
    uint32_t expectedCycles;

    if ((PlsrDiagnostic.flags & PLSR_DIAG_FLAG_MONITORING) == 0U)
    {
        return;
    }
#ifdef PLSR_HOST_TEST
    PlsrHostTestEventSequence++;
    PlsrHostTestLastDiagnosticFinishEvent = PlsrHostTestEventSequence;
#endif
    now = PlsrPlatformObservedPulses(
        (uint8_t)PlsrActiveConfig.pulseOutput);
    observed = (now >= PlsrDiagnosticSegmentCounterBase)
                   ? (now - PlsrDiagnosticSegmentCounterBase) : 0UL;
    if (observed > 0xFFFFFFFFUL)
    {
        PlsrDiagnostic.observedCycles = 0xFFFFFFFFUL;
        PlsrDiagnosticFailedChecks |= PLSR_DIAG_FLAG_COUNT_PASS;
        PlsrDiagnostic.flags &= (uint16_t)~PLSR_DIAG_FLAG_COUNT_PASS;
        PlsrDiagnosticLatch(PLSR_DIAG_REASON_INVALID_SAMPLE);
    }
    else
    {
        PlsrDiagnostic.observedCycles = (uint32_t)observed;
    }
    PlsrDiagnostic.flags &= (uint16_t)~PLSR_DIAG_FLAG_MONITORING;
    if (completedNormally == 0U)
    {
        PlsrDiagnostic.countError = 0L;
        PlsrDiagnostic.flags &= (uint16_t)~(PLSR_DIAG_FLAG_COUNT_CHECKED
                                            | PLSR_DIAG_FLAG_COUNT_PASS);
        return;
    }

    observedCycles = PlsrDiagnostic.observedCycles;
    expectedCycles = PlsrDiagnostic.expectedCycles;
    PlsrDiagnostic.countError =
        PlsrDifferenceI32(observedCycles, expectedCycles);
    PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_COUNT_CHECKED;
    if (PlsrDiagnostic.countError != 0L)
    {
        PlsrDiagnosticFailedChecks |= PLSR_DIAG_FLAG_COUNT_PASS;
        PlsrDiagnostic.flags &= (uint16_t)~PLSR_DIAG_FLAG_COUNT_PASS;
        PlsrDiagnosticLatch(PLSR_DIAG_REASON_COUNT);
    }
    else if ((PlsrDiagnosticFailedChecks & PLSR_DIAG_FLAG_COUNT_PASS) == 0U)
    {
        PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_COUNT_PASS;
    }
}

static void PlsrDiagnosticRecordFrequency(uint32_t requestedHz,
                                          uint32_t expectedHz,
                                          uint32_t actualHz)
{
    uint32_t error = PlsrAbsDifferenceU32(actualHz, expectedHz);

    PlsrDiagnostic.requestedHz = requestedHz;
    PlsrDiagnostic.expectedTimerHz = expectedHz;
    PlsrDiagnostic.activeTimerHz = actualHz;
    /* Request error is divider quantization, not a diagnostic deviation. */
    PlsrDiagnostic.requestErrorHz = PlsrDifferenceI32(expectedHz, requestedHz);
    PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_FREQUENCY_CHECKED;
    if (actualHz != expectedHz)
    {
        PlsrDiagnosticFailedChecks |= PLSR_DIAG_FLAG_FREQUENCY_PASS;
        PlsrDiagnostic.flags &= (uint16_t)~PLSR_DIAG_FLAG_FREQUENCY_PASS;
        PlsrDiagnosticLatch(PLSR_DIAG_REASON_FREQUENCY);
    }
    else if ((PlsrDiagnosticFailedChecks
              & PLSR_DIAG_FLAG_FREQUENCY_PASS) == 0U)
    {
        PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_FREQUENCY_PASS;
    }
    if (error > PlsrDiagnostic.curveMaxAbsErrorHz)
    {
        PlsrDiagnostic.curveMaxAbsErrorHz = error;
    }
}

static void PlsrDiagnosticRecordCurveSample(uint32_t expectedHz,
                                            uint32_t actualHz)
{
    uint32_t error = PlsrAbsDifferenceU32(expectedHz, actualHz);

    if (PlsrDiagnostic.curveSampleCount != 0xFFFFFFFFUL)
    {
        PlsrDiagnostic.curveSampleCount++;
    }
    PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_CURVE_CHECKED;
    if (error == 0UL)
    {
        if ((PlsrDiagnosticFailedChecks & PLSR_DIAG_FLAG_CURVE_PASS) == 0U)
        {
            PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_CURVE_PASS;
        }
    }
    else
    {
        PlsrDiagnosticFailedChecks |= PLSR_DIAG_FLAG_CURVE_PASS;
        PlsrDiagnostic.flags &= (uint16_t)~PLSR_DIAG_FLAG_CURVE_PASS;
        if (PlsrDiagnostic.curveMismatchCount != 0xFFFFFFFFUL)
        {
            PlsrDiagnostic.curveMismatchCount++;
        }
        if (PlsrDiagnostic.firstMismatchSample == 0xFFFFFFFFUL)
        {
            PlsrDiagnostic.firstMismatchSample =
                PlsrDiagnostic.curveSampleCount;
        }
        if (error > PlsrDiagnostic.curveMaxAbsErrorHz)
        {
            PlsrDiagnostic.curveMaxAbsErrorHz = error;
        }
        PlsrDiagnosticLatch(PLSR_DIAG_REASON_CURVE);
    }
}

static uint8_t PlsrDiagnosticStartPulse(uint8_t pulseOutput,
                                        uint32_t requestedFirstHz,
                                        uint32_t requestedQueuedHz,
                                        uint32_t *actualFirstHz,
                                        uint32_t *actualQueuedHz)
{
    PLSR_PLATFORM_TIMER_SETTING firstSetting;
    PLSR_PLATFORM_TIMER_SETTING queuedSetting;

    if ((PlsrPlatformBuildTimerSetting(
             pulseOutput, (uint8_t)PlsrActiveConfig.outputMode,
             requestedFirstHz, &firstSetting) == 0U)
        || (PlsrPlatformBuildTimerSetting(
                pulseOutput, (uint8_t)PlsrActiveConfig.outputMode,
                requestedQueuedHz, &queuedSetting) == 0U)
        || (PlsrPlatformStartPrepared(pulseOutput, &firstSetting,
                                      &queuedSetting, actualFirstHz,
                                      actualQueuedHz) == 0U))
    {
        PlsrDiagnosticFinishSegment(0U);
        return 0U;
    }
    PlsrDiagnosticRecordFrequency(requestedFirstHz,
                                  firstSetting.actualFrequencyHz,
                                  *actualFirstHz);
    PlsrDiagnosticRecordCurveSample(firstSetting.actualFrequencyHz,
                                    *actualFirstHz);
    PlsrDiagnosticQueuedExpectedHz = queuedSetting.actualFrequencyHz;
    return 1U;
}

static PLSR_PLATFORM_QUEUE_RESULT PlsrDiagnosticQueueFrequency(
    uint8_t pulseOutput,
    uint32_t requestedHz,
    uint32_t *actualHz)
{
    uint32_t expectedHz;
    PLSR_PLATFORM_QUEUE_RESULT result;

    if (PlsrPlatformExpectedFrequency(
            pulseOutput, (uint8_t)PlsrActiveConfig.outputMode,
            requestedHz, &expectedHz) == 0U)
    {
        PlsrDiagnosticFinishSegment(0U);
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    result = PlsrPlatformQueueFrequency(pulseOutput, requestedHz, actualHz);
    if (result == PLSR_PLATFORM_QUEUE_FAILED)
    {
        PlsrDiagnosticFinishSegment(0U);
        return result;
    }
    if (result == PLSR_PLATFORM_QUEUE_STALE)
    {
        return result;
    }

    PlsrDiagnosticRecordFrequency(requestedHz, expectedHz, *actualHz);
    PlsrDiagnosticQueuedExpectedHz = expectedHz;
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

static void PlsrDiagnosticCheckActiveFrequency(uint32_t activeHz)
{
    uint16_t platformFault = PlsrPlatformDiagnosticFault();
    uint32_t observedHz = activeHz;

    if (platformFault == PLSR_DIAG_REASON_FREQUENCY)
    {
        observedHz = PlsrPlatformActiveFrequency(
            (uint8_t)PlsrActiveConfig.pulseOutput);
        if (observedHz == 0UL)
        {
            observedHz = activeHz;
        }
        PlsrDiagnosticFailedChecks |= PLSR_DIAG_FLAG_FREQUENCY_PASS;
        PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_FREQUENCY_CHECKED;
        PlsrDiagnostic.flags &= (uint16_t)~PLSR_DIAG_FLAG_FREQUENCY_PASS;
        PlsrDiagnosticLatch(PLSR_DIAG_REASON_FREQUENCY);
    }
    if ((platformFault != PLSR_DIAG_REASON_NONE)
        && (PlsrDiagnosticQueuedExpectedHz != 0UL))
    {
        PlsrDiagnostic.activeTimerHz = observedHz;
        if (platformFault == PLSR_DIAG_REASON_CURVE)
        {
            if (PlsrDiagnostic.curveSampleCount != 0xFFFFFFFFUL)
            {
                PlsrDiagnostic.curveSampleCount++;
            }
            PlsrDiagnostic.flags |= PLSR_DIAG_FLAG_CURVE_CHECKED;
            PlsrDiagnostic.flags &= (uint16_t)~PLSR_DIAG_FLAG_CURVE_PASS;
            PlsrDiagnosticFailedChecks |= PLSR_DIAG_FLAG_CURVE_PASS;
            if (PlsrDiagnostic.curveMismatchCount != 0xFFFFFFFFUL)
            {
                PlsrDiagnostic.curveMismatchCount++;
            }
            if (PlsrDiagnostic.firstMismatchSample == 0xFFFFFFFFUL)
            {
                PlsrDiagnostic.firstMismatchSample =
                    PlsrDiagnostic.curveSampleCount;
            }
            PlsrDiagnosticLatch(PLSR_DIAG_REASON_CURVE);
        }
        else if (platformFault == PLSR_DIAG_REASON_FREQUENCY)
        {
            PlsrDiagnosticRecordCurveSample(PlsrDiagnosticQueuedExpectedHz,
                                            observedHz);
        }
    }
}

static void PlsrSetDefaults(PLSR_CONFIG *config)
{
    uint8_t index;

    (void)memset(config, 0, sizeof(*config));
    config->pulseOutput = 0U;
    config->directionOutput = 0U;
    config->waitInput = 0U;
    config->extInput = 0U;
    config->sendMode = PLSR_SEND_COMPLETE;
    config->directionDelayMs = 10U;
    config->directionNegativeLogic = 0U;
    config->curveMode = 0U;
    config->positionMode = PLSR_POSITION_RELATIVE;
    config->segmentCount = 1U;
    config->startSegment = 1U;
    config->defaultSpeedHz = 1000UL;
    config->startSpeedHz = 100UL;
    config->stopSpeedHz = 100UL;
    config->accelerationTimeMs = 100U;
    config->decelerationTimeMs = 100U;
    config->outputMode = PLSR_OUTPUT_PULSE_DIR;

    for (index = 0U; index < PLSR_SEGMENT_COUNT_MAX; index++)
    {
        config->segments[index].frequencyHz = 1000UL;
        config->segments[index].pulses = (index == 0U) ? 1000L : 0L;
        config->segments[index].waitType = PLSR_EXT_OR_COMPLETE;
        config->segments[index].waitTimeMs = 0U;
        config->segments[index].actTimeMs = 0U;
        config->segments[index].jumpSegment = 0U;
    }
}

static uint8_t PlsrConfigIsValid(const PLSR_CONFIG *config,
                                 uint8_t validateActivePath)
{
    uint8_t index;

    if ((config->pulseOutput > 3U) || (config->directionOutput > 3U)
        || (config->waitInput > 1U) || (config->extInput > 1U)
        || (config->sendMode > PLSR_SEND_SUBSEQUENT)
        || (config->directionNegativeLogic > 1U)
        || (config->curveMode > 2U)
        || (config->positionMode > PLSR_POSITION_ABSOLUTE)
        || (config->outputMode > PLSR_OUTPUT_AB)
        || ((config->outputMode == PLSR_OUTPUT_AB)
            && ((config->pulseOutput & 1U) != 0U))
        || (config->segmentCount == 0U)
        || (config->segmentCount > PLSR_SEGMENT_COUNT_MAX)
        || (config->startSegment == 0U)
        || (config->startSegment > PLSR_SEGMENT_COUNT_MAX)
        || (config->defaultSpeedHz == 0UL)
        || (config->defaultSpeedHz > PLSR_FREQUENCY_MAX_HZ)
        || (config->startSpeedHz > PLSR_FREQUENCY_MAX_HZ)
        || (config->stopSpeedHz > PLSR_FREQUENCY_MAX_HZ))
    {
        return 0U;
    }

    if ((validateActivePath != 0U)
        && (config->startSegment > config->segmentCount))
    {
        return 0U;
    }

    for (index = 0U; index < PLSR_SEGMENT_COUNT_MAX; index++)
    {
        const PLSR_SEGMENT_CONFIG *segment = &config->segments[index];

        if ((segment->frequencyHz > PLSR_FREQUENCY_MAX_HZ)
            || (segment->waitType > PLSR_EXT_OR_COMPLETE)
            || (segment->jumpSegment > PLSR_SEGMENT_COUNT_MAX))
        {
            return 0U;
        }

        if ((validateActivePath != 0U)
            && (index < config->segmentCount)
            && (segment->jumpSegment > config->segmentCount))
        {
            return 0U;
        }
    }

    return 1U;
}

static uint16_t PlsrReadConfigWord(const PLSR_CONFIG *config,
                                   uint16_t address)
{
    uint16_t offset;
    uint8_t segmentIndex;
    const PLSR_SEGMENT_CONFIG *segment;

    switch (address)
    {
        case 0x1000U: return config->pulseOutput;
        case 0x1001U: return config->directionOutput;
        case 0x1002U: return config->waitInput;
        case 0x1003U: return config->extInput;
        case 0x1004U: return config->sendMode;
        case 0x1005U: return config->directionDelayMs;
        case 0x1006U: return config->directionNegativeLogic;
        case 0x1007U: return config->curveMode;
        case 0x1008U: return config->positionMode;
        case 0x1009U: return config->segmentCount;
        case 0x100AU: return config->startSegment;
        case 0x100BU: return PlsrLowWord(config->defaultSpeedHz);
        case 0x100CU: return PlsrHighWord(config->defaultSpeedHz);
        case 0x100DU: return PlsrLowWord(config->startSpeedHz);
        case 0x100EU: return PlsrHighWord(config->startSpeedHz);
        case 0x1010U: return PlsrLowWord(config->stopSpeedHz);
        case 0x1011U: return PlsrHighWord(config->stopSpeedHz);
        case 0x1012U: return config->accelerationTimeMs;
        case 0x1013U: return config->decelerationTimeMs;
        default: break;
    }

    if ((address >= PLSR_SEGMENT_FIRST_ADDRESS)
        && (address <= PLSR_CONFIG_LAST_ADDRESS))
    {
        offset = (uint16_t)(address - PLSR_SEGMENT_FIRST_ADDRESS);
        segmentIndex = (uint8_t)(offset / PLSR_SEGMENT_STRIDE);
        offset = (uint16_t)(offset % PLSR_SEGMENT_STRIDE);
        segment = &config->segments[segmentIndex];

        switch (offset)
        {
            case 0U: return PlsrLowWord(segment->frequencyHz);
            case 1U: return PlsrHighWord(segment->frequencyHz);
            case 2U: return PlsrLowWord((uint32_t)segment->pulses);
            case 3U: return PlsrHighWord((uint32_t)segment->pulses);
            case 4U: return segment->waitType;
            case 5U: return segment->waitTimeMs;
            case 6U: return segment->actTimeMs;
            case 7U: return segment->jumpSegment;
            default: return 0U;
        }
    }

    /* 0x100F, 0x1014..0x10FF, and segment padding read as zero. */
    return 0U;
}

static PLSR_WORD_RESULT PlsrWriteConfigWord(PLSR_CONFIG *config,
                                            uint16_t address,
                                            uint16_t value)
{
    uint16_t offset;
    uint8_t segmentIndex;
    PLSR_SEGMENT_CONFIG *segment;

    switch (address)
    {
        case 0x1000U: config->pulseOutput = value; return PLSR_WORD_OK;
        case 0x1001U: config->directionOutput = value; return PLSR_WORD_OK;
        case 0x1002U: config->waitInput = value; return PLSR_WORD_OK;
        case 0x1003U: config->extInput = value; return PLSR_WORD_OK;
        case 0x1004U: config->sendMode = value; return PLSR_WORD_OK;
        case 0x1005U: config->directionDelayMs = value; return PLSR_WORD_OK;
        case 0x1006U:
            config->directionNegativeLogic = value;
            return PLSR_WORD_OK;
        case 0x1007U: config->curveMode = value; return PLSR_WORD_OK;
        case 0x1008U: config->positionMode = value; return PLSR_WORD_OK;
        case 0x1009U: config->segmentCount = value; return PLSR_WORD_OK;
        case 0x100AU: config->startSegment = value; return PLSR_WORD_OK;
        case 0x100BU:
            config->defaultSpeedHz =
                PlsrJoinU32(value, PlsrHighWord(config->defaultSpeedHz));
            return PLSR_WORD_OK;
        case 0x100CU:
            config->defaultSpeedHz =
                PlsrJoinU32(PlsrLowWord(config->defaultSpeedHz), value);
            return PLSR_WORD_OK;
        case 0x100DU:
            config->startSpeedHz =
                PlsrJoinU32(value, PlsrHighWord(config->startSpeedHz));
            return PLSR_WORD_OK;
        case 0x100EU:
            config->startSpeedHz =
                PlsrJoinU32(PlsrLowWord(config->startSpeedHz), value);
            return PLSR_WORD_OK;
        case 0x100FU:
            return (value == 0U) ? PLSR_WORD_OK : PLSR_WORD_ILLEGAL_VALUE;
        case 0x1010U:
            config->stopSpeedHz =
                PlsrJoinU32(value, PlsrHighWord(config->stopSpeedHz));
            return PLSR_WORD_OK;
        case 0x1011U:
            config->stopSpeedHz =
                PlsrJoinU32(PlsrLowWord(config->stopSpeedHz), value);
            return PLSR_WORD_OK;
        case 0x1012U:
            config->accelerationTimeMs = value;
            return PLSR_WORD_OK;
        case 0x1013U:
            config->decelerationTimeMs = value;
            return PLSR_WORD_OK;
        default: break;
    }

    if ((address >= 0x1014U) && (address <= PLSR_COMMON_LAST_ADDRESS))
    {
        return (value == 0U) ? PLSR_WORD_OK : PLSR_WORD_ILLEGAL_VALUE;
    }

    if ((address < PLSR_SEGMENT_FIRST_ADDRESS)
        || (address > PLSR_CONFIG_LAST_ADDRESS))
    {
        return PLSR_WORD_ILLEGAL_ADDRESS;
    }

    offset = (uint16_t)(address - PLSR_SEGMENT_FIRST_ADDRESS);
    segmentIndex = (uint8_t)(offset / PLSR_SEGMENT_STRIDE);
    offset = (uint16_t)(offset % PLSR_SEGMENT_STRIDE);
    segment = &config->segments[segmentIndex];

    switch (offset)
    {
        case 0U:
            segment->frequencyHz =
                PlsrJoinU32(value, PlsrHighWord(segment->frequencyHz));
            return PLSR_WORD_OK;
        case 1U:
            segment->frequencyHz =
                PlsrJoinU32(PlsrLowWord(segment->frequencyHz), value);
            return PLSR_WORD_OK;
        case 2U:
            segment->pulses = (int32_t)PlsrJoinU32(
                value, PlsrHighWord((uint32_t)segment->pulses));
            return PLSR_WORD_OK;
        case 3U:
            segment->pulses = (int32_t)PlsrJoinU32(
                PlsrLowWord((uint32_t)segment->pulses), value);
            return PLSR_WORD_OK;
        case 4U: segment->waitType = value; return PLSR_WORD_OK;
        case 5U: segment->waitTimeMs = value; return PLSR_WORD_OK;
        case 6U: segment->actTimeMs = value; return PLSR_WORD_OK;
        case 7U: segment->jumpSegment = value; return PLSR_WORD_OK;
        default:
            return (value == 0U) ? PLSR_WORD_OK : PLSR_WORD_ILLEGAL_VALUE;
    }
}

static uint8_t PlsrAddressIsDwordHalf(uint16_t address,
                                      uint16_t *pairedAddress)
{
    uint16_t offset;

    switch (address)
    {
        case 0x100BU: case 0x100DU: case 0x1010U:
            *pairedAddress = (uint16_t)(address + 1U);
            return 1U;
        case 0x100CU: case 0x100EU: case 0x1011U:
            *pairedAddress = (uint16_t)(address - 1U);
            return 1U;
        default: break;
    }

    if ((address >= PLSR_SEGMENT_FIRST_ADDRESS)
        && (address <= PLSR_CONFIG_LAST_ADDRESS))
    {
        offset = (uint16_t)((address - PLSR_SEGMENT_FIRST_ADDRESS)
                            % PLSR_SEGMENT_STRIDE);
        if ((offset == 0U) || (offset == 2U))
        {
            *pairedAddress = (uint16_t)(address + 1U);
            return 1U;
        }
        if ((offset == 1U) || (offset == 3U))
        {
            *pairedAddress = (uint16_t)(address - 1U);
            return 1U;
        }
    }

    return 0U;
}

static uint8_t PlsrAddressIsProduct(uint16_t address)
{
    return (((address >= PLSR_CONFIG_FIRST_ADDRESS)
             && (address <= PLSR_CONFIG_LAST_ADDRESS))
            || (address == PLSR_OUTPUT_MODE_ADDRESS)
            || ((address >= PLSR_STATUS_FIRST_ADDRESS)
                && (address <= PLSR_STATUS_LAST_ADDRESS))
            || ((address >= PLSR_DIAGNOSTIC_FIRST_ADDRESS)
                && (address <= PLSR_DIAGNOSTIC_LAST_ADDRESS))
            || (address == PLSR_CONTROL_ADDRESS)
            || (address == PLSR_DIAGNOSTIC_CONTROL_ADDRESS)) ? 1U : 0U;
}

static PLSR_MB_RESULT PlsrClassifyRange(uint16_t startAddress,
                                        uint16_t quantity)
{
    uint32_t address;
    uint32_t endAddress;
    uint8_t foundProduct = 0U;
    uint8_t foundOther = 0U;

    if (quantity == 0U)
    {
        return PLSR_MB_ILLEGAL_VALUE;
    }

    endAddress = (uint32_t)startAddress + (uint32_t)quantity - 1UL;
    if (endAddress > 0xFFFFUL)
    {
        return PLSR_MB_ILLEGAL_ADDRESS;
    }

    for (address = startAddress; address <= endAddress; address++)
    {
        if (PlsrAddressIsProduct((uint16_t)address) != 0U)
        {
            foundProduct = 1U;
        }
        else
        {
            foundOther = 1U;
        }
    }

    if (foundProduct == 0U)
    {
        return PLSR_MB_NOT_HANDLED;
    }
    return (foundOther != 0U) ? PLSR_MB_ILLEGAL_ADDRESS : PLSR_MB_OK;
}

static uint32_t PlsrCurveProgressQ16(uint32_t elapsed,
                                     uint32_t duration,
                                     uint16_t curveMode)
{
    uint32_t linear;

    if ((duration == 0UL) || (elapsed >= duration))
    {
        return 65535UL;
    }

    linear = (uint32_t)(((uint64_t)elapsed * 65535UL) / duration);
    if (curveMode == 1U)
    {
        uint64_t x = linear;
        uint64_t x2 = (x * x) / 65535UL;
        return (uint32_t)((x2 * (196605UL - 2UL * x)) / 65535UL);
    }
    if (curveMode == 2U)
    {
        uint32_t scaled = linear * 64UL;
        uint32_t index = scaled / 65535UL;
        uint32_t fraction = scaled % 65535UL;
        uint32_t first;
        uint32_t second;

        if (index >= 64UL)
        {
            return 65535UL;
        }
        first = PlsrSineProgressQ16[index];
        second = PlsrSineProgressQ16[index + 1UL];
        return first + (uint32_t)(((uint64_t)(second - first) * fraction)
                                  / 65535UL);
    }
    return linear;
}

static uint32_t PlsrRampDurationMs(uint32_t fromHz, uint32_t toHz)
{
    uint32_t gap;
    uint32_t baseTimeMs;
    uint64_t duration;

    if (fromHz == toHz)
    {
        return 0UL;
    }
    gap = (fromHz > toHz) ? (fromHz - toHz) : (toHz - fromHz);
    baseTimeMs = (toHz > fromHz) ? PlsrActiveConfig.accelerationTimeMs
                                 : PlsrActiveConfig.decelerationTimeMs;
    if (baseTimeMs == 0UL)
    {
        return 0UL;
    }

    duration = ((uint64_t)gap * baseTimeMs
                + PlsrActiveConfig.defaultSpeedHz - 1UL)
               / PlsrActiveConfig.defaultSpeedHz;
    if (duration > 0xFFFFFFFFUL)
    {
        return 0xFFFFFFFFUL;
    }
    return (uint32_t)duration;
}

static uint32_t PlsrEffectiveStartFrequency(uint32_t segmentFrequencyHz,
                                            uint8_t allowCarry,
                                            uint8_t directionChanged,
                                            uint32_t carryFrequencyHz)
{
    if ((allowCarry != 0U) && (directionChanged == 0U)
        && (carryFrequencyHz != 0UL))
    {
        return carryFrequencyHz;
    }
    if (PlsrActiveConfig.accelerationTimeMs == 0U)
    {
        return segmentFrequencyHz;
    }
    return PlsrActiveConfig.startSpeedHz;
}

static uint32_t PlsrEffectiveStopFrequency(uint32_t segmentFrequencyHz)
{
    return (PlsrActiveConfig.decelerationTimeMs == 0U)
               ? segmentFrequencyHz : PlsrActiveConfig.stopSpeedHz;
}

static void PlsrRampStart(uint32_t fromHz, uint32_t toHz)
{
    PlsrRamp.fromHz = fromHz;
    PlsrRamp.toHz = toHz;
    PlsrRamp.durationMs = PlsrRampDurationMs(fromHz, toHz);
    PlsrRamp.elapsedMs = 0UL;
    PlsrRamp.active = (PlsrRamp.durationMs != 0UL) ? 1U : 0U;

    if (toHz > fromHz)
    {
        PlsrRunStatus = PLSR_STATUS_ACCELERATING;
    }
    else if (toHz < fromHz)
    {
        PlsrRunStatus = PLSR_STATUS_DECELERATING;
    }
    else
    {
        PlsrRunStatus = PLSR_STATUS_RUNNING;
    }
}

static uint8_t PlsrApplyFrequencyPair(uint32_t requestedFirstFrequencyHz,
                                      uint32_t requestedQueuedFrequencyHz,
                                      uint32_t expectedEpoch)
{
    uint32_t criticalState;
    uint32_t actualFirstFrequencyHz;
    uint32_t actualQueuedFrequencyHz;
    uint32_t hardwareFirstFrequencyHz = requestedFirstFrequencyHz;
    uint32_t hardwareQueuedFrequencyHz = requestedQueuedFrequencyHz;
    PLSR_HANDOFF_PLAN candidatePlan;
    uint8_t haveCandidatePlan = 0U;

    criticalState = PlsrPlatformEnterCritical();
    if ((PlsrSegmentEpoch != expectedEpoch)
        || (PlsrBoundaryPending != 0U) || (PlsrRemainingPulses == 0UL))
    {
        PlsrPlatformExitCritical(criticalState);
        return 1U;
    }

    if (hardwareFirstFrequencyHz == 0UL)
    {
        if (PlsrPulseActive == 0U)
        {
            PlsrCurrentFrequencyHz = 0UL;
            PlsrQueuedFrequencyHz = 0UL;
            PlsrPlatformExitCritical(criticalState);
            return 1U;
        }
        hardwareFirstFrequencyHz = 1UL;
    }
    if (hardwareQueuedFrequencyHz == 0UL)
    {
        hardwareQueuedFrequencyHz = 1UL;
    }

    if (PlsrPulseActive != 0U)
    {
        if (PlsrAbStopArmed != 0U)
        {
            PlsrPlatformExitCritical(criticalState);
            return 1U;
        }
        if (PlsrHandoffPlan.valid != 0U)
        {
            PlsrPlatformExitCritical(criticalState);
            return 1U;
        }
        PlsrDeferredFrequencyHz = hardwareQueuedFrequencyHz;
        PlsrDeferredFrequencyPending = 1U;
        PlsrPlatformExitCritical(criticalState);
        return 1U;
    }
    else
    {
        if (PlsrSelectPreparedHandoffPlan(&candidatePlan) != 0U)
        {
            hardwareQueuedFrequencyHz = candidatePlan.firstFrequencyHz;
            haveCandidatePlan = 1U;
        }
        if (PlsrDiagnosticStartPulse(
                (uint8_t)PlsrActiveConfig.pulseOutput,
                hardwareFirstFrequencyHz, hardwareQueuedFrequencyHz,
                &actualFirstFrequencyHz, &actualQueuedFrequencyHz) == 0U)
        {
            PlsrPlatformExitCritical(criticalState);
            return 0U;
        }
        PlsrPulseActive = 1U;
        PlsrCurrentFrequencyHz = actualFirstFrequencyHz;
        PlsrHandoffPlan.valid = 0U;
        if (haveCandidatePlan != 0U)
        {
            PlsrHandoffPlan = candidatePlan;
            PlsrHandoffPlan.firstFrequencyHz = actualQueuedFrequencyHz;
            PlsrHandoffPlan.valid = 1U;
        }
    }

    PlsrQueuedFrequencyHz = actualQueuedFrequencyHz;
    if (PlsrArmFinalAbBoundaryLocked() == 0U)
    {
        PlsrPlatformExitCritical(criticalState);
        return 0U;
    }
    PlsrPlatformExitCritical(criticalState);
    return 1U;
}

static PLSR_PLATFORM_QUEUE_RESULT PlsrApplyFrequency(
    uint32_t requestedFrequencyHz,
    uint32_t expectedEpoch)
{
    return (PlsrApplyFrequencyPair(requestedFrequencyHz,
                                   requestedFrequencyHz,
                                   expectedEpoch) != 0U)
               ? PLSR_PLATFORM_QUEUE_APPLIED
               : PLSR_PLATFORM_QUEUE_FAILED;
}

static uint8_t PlsrStopDrainPulseCount(void)
{
    uint8_t deferredPending = PlsrDeferredFrequencyPending;
    uint32_t deferredFrequencyHz = PlsrDeferredFrequencyHz;
    uint32_t queuedFrequencyHz = PlsrQueuedFrequencyHz;
    uint32_t currentFrequencyHz = PlsrCurrentFrequencyHz;

    if ((deferredPending != 0U)
        && (deferredFrequencyHz != queuedFrequencyHz))
    {
        return 3U;
    }
    PlsrDeferredFrequencyPending = 0U;
    return (currentFrequencyHz == queuedFrequencyHz) ? 1U : 2U;
}

static uint8_t PlsrArmStopDrainLocked(void)
{
    uint32_t drainPulses = PlsrStopDrainPulseCount();

    PlsrStopPulsesRemaining = (uint8_t)drainPulses;
    return PlsrArmFinalAbBoundaryLocked();
}

static PLSR_PLATFORM_QUEUE_RESULT PlsrCommitDeferredFrequency(
    uint8_t pulseOutput)
{
    uint32_t requestedFrequencyHz;
    uint32_t actualFrequencyHz;
    PLSR_PLATFORM_QUEUE_RESULT result;

    if (PlsrDeferredFrequencyPending == 0U)
    {
        return PLSR_PLATFORM_QUEUE_APPLIED;
    }
    requestedFrequencyHz = PlsrDeferredFrequencyHz;
    result = PlsrDiagnosticQueueFrequency(pulseOutput, requestedFrequencyHz,
                                          &actualFrequencyHz);
    if (result != PLSR_PLATFORM_QUEUE_APPLIED)
    {
        return result;
    }
    if ((PlsrDeferredFrequencyPending != 0U)
        && (PlsrDeferredFrequencyHz == requestedFrequencyHz))
    {
        PlsrDeferredFrequencyPending = 0U;
    }
    PlsrQueuedFrequencyHz = actualFrequencyHz;
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

static uint8_t PlsrRampAdvance(uint32_t expectedEpoch)
{
    uint32_t progress;
    uint32_t frequency;
    uint32_t gap;
    uint32_t criticalState;
    uint32_t fromHz;
    uint32_t toHz;
    uint32_t durationMs;
    uint32_t elapsedMs;
    PLSR_PLATFORM_QUEUE_RESULT applyResult;

    criticalState = PlsrPlatformEnterCritical();
    if ((PlsrSegmentEpoch != expectedEpoch) || (PlsrRamp.active == 0U))
    {
        PlsrPlatformExitCritical(criticalState);
        return 1U;
    }
    if (PlsrRamp.elapsedMs < PlsrRamp.durationMs)
    {
        PlsrRamp.elapsedMs++;
    }
    fromHz = PlsrRamp.fromHz;
    toHz = PlsrRamp.toHz;
    durationMs = PlsrRamp.durationMs;
    elapsedMs = PlsrRamp.elapsedMs;
    PlsrPlatformExitCritical(criticalState);

    progress = PlsrCurveProgressQ16(elapsedMs,
                                    durationMs,
                                    PlsrActiveConfig.curveMode);
    if (toHz >= fromHz)
    {
        gap = toHz - fromHz;
        frequency = fromHz
                    + (uint32_t)(((uint64_t)gap * progress) / 65535UL);
    }
    else
    {
        gap = fromHz - toHz;
        frequency = fromHz
                    - (uint32_t)(((uint64_t)gap * progress) / 65535UL);
    }

    applyResult = PlsrApplyFrequency(frequency, expectedEpoch);
    if (applyResult == PLSR_PLATFORM_QUEUE_FAILED)
    {
        return 0U;
    }
    if (applyResult == PLSR_PLATFORM_QUEUE_STALE)
    {
        return 1U;
    }

    criticalState = PlsrPlatformEnterCritical();
    if (PlsrSegmentEpoch != expectedEpoch)
    {
        PlsrPlatformExitCritical(criticalState);
        return 1U;
    }
    if (elapsedMs >= durationMs)
    {
        PlsrRamp.active = 0U;
        if (PlsrStopRequested == 0U)
        {
            PlsrRunStatus = PLSR_STATUS_RUNNING;
        }
        else
        {
            (void)PlsrArmStopDrainLocked();
        }
    }
    PlsrPlatformExitCritical(criticalState);
    return 1U;
}

static uint8_t PlsrGetNextSegment(uint8_t *nextSegment)
{
    const PLSR_SEGMENT_CONFIG *segment =
        &PlsrActiveConfig.segments[PlsrCurrentSegment - 1U];

    if (segment->jumpSegment != 0U)
    {
        *nextSegment = (uint8_t)segment->jumpSegment;
        return 1U;
    }
    if (PlsrCurrentSegment < PlsrActiveConfig.segmentCount)
    {
        *nextSegment = (uint8_t)(PlsrCurrentSegment + 1U);
        return 1U;
    }
    return 0U;
}

static uint32_t PlsrResolvedSegmentFrequency(const PLSR_CONFIG *config,
                                             uint8_t segmentIndex)
{
    uint32_t frequencyHz = config->segments[segmentIndex].frequencyHz;

    return (frequencyHz == 0UL) ? config->defaultSpeedHz : frequencyHz;
}

static int64_t PlsrSegmentDisplacement(uint8_t segmentNumber,
                                       int32_t referencePosition)
{
    int32_t configured =
        PlsrActiveConfig.segments[segmentNumber - 1U].pulses;

    if (PlsrActiveConfig.positionMode == PLSR_POSITION_ABSOLUTE)
    {
        return (int64_t)configured - (int64_t)referencePosition;
    }
    return configured;
}

static uint8_t PlsrPredictNextDirection(uint8_t nextSegment,
                                        uint8_t *positive)
{
    uint32_t criticalState;
    uint64_t remaining;
    int32_t position;
    uint32_t predictedBits;
    int32_t predictedPosition;
    int64_t displacement;

    criticalState = PlsrPlatformEnterCritical();
    remaining = PlsrRemainingPulses;
    position = PlsrPosition;
    PlsrPlatformExitCritical(criticalState);

    predictedBits = (uint32_t)position;
    if (PlsrCountPositive != 0U)
    {
        predictedBits += (uint32_t)remaining;
    }
    else
    {
        predictedBits -= (uint32_t)remaining;
    }
    predictedPosition = (int32_t)predictedBits;
    displacement = PlsrSegmentDisplacement(nextSegment, predictedPosition);
    if (displacement == 0)
    {
        return 0U;
    }
    *positive = (displacement > 0) ? 1U : 0U;
    return 1U;
}

static uint64_t PlsrRemainingSnapshot(void)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();
    uint64_t remaining = PlsrRemainingPulses;
    PlsrPlatformExitCritical(criticalState);
    return remaining;
}

static uint64_t PlsrRampPulseEstimate(uint32_t fromHz,
                                      uint32_t toHz,
                                      uint32_t rateBoundHz)
{
    uint32_t duration = PlsrRampDurationMs(fromHz, toHz);
    uint64_t sum = (uint64_t)fromHz + toHz;
    uint64_t discreteArea = sum * duration;
    uint64_t rampArea;
    uint64_t pollReserve = 0ULL;
    uint64_t candidateReserve =
        ((uint64_t)rateBoundHz + 999UL) / 1000UL;
    uint64_t endpointCorrection = 0ULL;

    /* RampAdvance applies samples at 1/duration through duration/duration.
       For all supported symmetric curves this right-endpoint sum differs
       from the continuous trapezoid by half the endpoint delta. */
    if (toHz >= fromHz)
    {
        discreteArea += (uint64_t)toHz - fromHz;
    }
    else
    {
        discreteArea -= (uint64_t)fromHz - toHz;
        endpointCorrection =
            ((uint64_t)fromHz - toHz + 1999UL) / 2000UL;
    }
    rampArea = (discreteArea + 1999UL) / 2000UL;

    if (candidateReserve
        <= rampArea / PLSR_RAMP_POLL_RESERVE_AREA_DIVISOR)
    {
        pollReserve = candidateReserve + endpointCorrection;
    }

    /* A full poll reserve on shorter ramps would dominate their area and
       leave stop-speed tail pulses. */
    return rampArea + pollReserve;
}

static uint8_t PlsrPrepareShortProfile(PLSR_SHORT_PROFILE *profile,
                                       uint8_t segmentNumber,
                                       uint32_t startFrequencyHz,
                                       uint32_t targetFrequencyHz,
                                       uint64_t pulseCount)
{
    PLSR_MOTION_BLOCK block;
    PLSR_PLANNER_STATUS status;
    const PLSR_SEGMENT_CONFIG *segment;
    uint8_t nextSegment = 0U;
    uint8_t currentPositive;
    uint8_t nextPositive;

    (void)memset(profile, 0, sizeof(*profile));
    if ((PlsrActiveConfig.outputMode != PLSR_OUTPUT_PULSE_DIR)
        || (pulseCount == 0ULL) || (pulseCount > 0xFFFFFFFFULL)
        || (segmentNumber == 0U)
        || (segmentNumber > PlsrActiveConfig.segmentCount))
    {
        return 0U;
    }

    block.entryHz = startFrequencyHz;
    block.cruiseHz = targetFrequencyHz;
    block.exitHz = PlsrEffectiveStopFrequency(targetFrequencyHz);
    block.pulseBudget = (uint32_t)pulseCount;
    block.referenceSpeedHz = PlsrActiveConfig.defaultSpeedHz;
    block.accelerationTimeMs = PlsrActiveConfig.accelerationTimeMs;
    block.decelerationTimeMs = PlsrActiveConfig.decelerationTimeMs;
    block.curveMode = PlsrActiveConfig.curveMode;
    block.pulseOutput = (uint8_t)PlsrActiveConfig.pulseOutput;
    block.boundary = PLSR_BOUNDARY_STOP;

    segment = &PlsrActiveConfig.segments[segmentNumber - 1U];
    if (segment->waitType == PLSR_EXT_OR_COMPLETE)
    {
        nextSegment = (segment->jumpSegment != 0U)
                          ? (uint8_t)segment->jumpSegment
                          : ((segmentNumber < PlsrActiveConfig.segmentCount)
                                 ? (uint8_t)(segmentNumber + 1U) : 0U);
    }
    if (nextSegment != 0U)
    {
        currentPositive = PlsrCountPositive;
        if (PlsrActiveConfig.positionMode == PLSR_POSITION_RELATIVE)
        {
            currentPositive = (segment->pulses >= 0L) ? 1U : 0U;
            nextPositive =
                (PlsrActiveConfig.segments[nextSegment - 1U].pulses >= 0L)
                    ? 1U : 0U;
        }
        else if ((segmentNumber == PlsrCurrentSegment)
                 && (PlsrPredictNextDirection(nextSegment,
                                              &nextPositive) != 0U))
        {
            /* direction resolved from the live absolute position */
        }
        else
        {
            nextPositive = (uint8_t)(currentPositive ^ 1U);
        }
        if (nextPositive == currentPositive)
        {
            block.exitHz = targetFrequencyHz;
            block.boundary = PLSR_BOUNDARY_NEXT_CARRY;
        }
    }

    status = PlsrPlannerBegin(&profile->planner, &block,
                              startFrequencyHz, 0ULL);
    if ((status != PLSR_PLANNER_OK)
        && (status != PLSR_PLANNER_CLIPPED))
    {
        return 0U;
    }
    profile->startHz = profile->planner.startHz;
    profile->peakHz = profile->planner.peakHz;
    profile->endHz = profile->planner.endHz;
    profile->pulseCount = profile->planner.block.pulseBudget;
    profile->entryPulses = profile->planner.entryPulses;
    profile->steadyPulses = profile->planner.steadyPulses;
    profile->exitPulses = profile->planner.exitPulses;
    profile->active = ((profile->startHz != profile->peakHz)
                       || (profile->peakHz != profile->endHz))
                          ? 1U : 0U;
    return 1U;
}

static uint32_t PlsrShortProfileTakeFrequency(PLSR_SHORT_PROFILE *profile)
{
    uint32_t frequencyHz;

    if ((profile->active == 0U)
        || (profile->nextPeriod >= profile->pulseCount))
    {
        return (profile->endHz == 0UL) ? 1UL : profile->endHz;
    }
    if (profile->pendingRepeats == 0UL)
    {
        if (PlsrPlannerGenerate(&profile->planner,
                                &profile->pendingItem, 1U) == 0U)
        {
            profile->active = 0U;
            return (profile->endHz == 0UL) ? 1UL : profile->endHz;
        }
        profile->pendingRepeats = profile->pendingItem.repeatCount;
    }

    frequencyHz = profile->pendingItem.setting.actualFrequencyHz;
    profile->pendingRepeats--;
    profile->nextPeriod++;
    profile->lastRampFrequencyHz = frequencyHz;
    if (profile->nextPeriod >= profile->pulseCount)
    {
        profile->active = 0U;
    }
    return frequencyHz;
}

/* Caller holds the platform critical section.  The currently preloaded
   period is the single committed pulse; the new stream starts after it. */
static uint8_t PlsrReplanPulseDir(uint32_t targetHz,
                                  uint32_t totalPulses)
{
    uint32_t appliedHz;
    uint32_t epoch;
    uint8_t segmentNumber;
    uint8_t handoffBank;

    PlsrRamp.active = 0U;
    PlsrShortProfile.active = 0U;
    PlsrProfileQueueInvalidateGeneration();
    PlsrHandoffPlan.valid = 0U;
    if (totalPulses <= 1UL)
    {
        return 1U;
    }

    appliedHz = PlsrQueuedFrequencyHz;
    if (appliedHz == 0UL)
    {
        appliedHz = PlsrCurrentFrequencyHz;
    }
    if ((appliedHz == 0UL)
        || (PlsrPrepareShortProfile(&PlsrShortProfile,
                                    PlsrCurrentSegment,
                                    appliedHz, targetHz,
                                    totalPulses - 1UL) == 0U))
    {
        return 0U;
    }
    PlsrRefreshCurrentHandoffPlan(PlsrShortProfile.endHz);

    epoch = PlsrSegmentEpoch;
    segmentNumber = PlsrCurrentSegment;
    handoffBank = PlsrPreparedHandoffBank;
    (void)PlsrProfileQueueBegin(&PlsrShortProfile, epoch,
                                segmentNumber, handoffBank);
    if (PlsrProfileQueueFill(PLSR_REPLAN_WARMUP_ITEMS) == 0U)
    {
        PlsrProfileQueueReset();
        PlsrShortProfile.active = 0U;
        return 0U;
    }
    PlsrExecutor.generation++;
    PlsrExecutor.mode = PLSR_EXEC_STREAM;
    return 1U;
}

static void PlsrCopyShortProfile(PLSR_SHORT_PROFILE *destination,
                                 const PLSR_SHORT_PROFILE *source)
{
    *destination = *source;
}

static uint16_t PlsrProfileQueueCount(void)
{
    uint32_t writeIndex = PlsrProfileQueue.writeIndex;
    uint32_t readIndex = PlsrProfileQueue.readIndex;

    return (uint16_t)(writeIndex - readIndex);
}

static void PlsrProfileQueueReset(void)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();

    PlsrProfileQueue.generation++;
    PlsrProfileQueue.readIndex = 0U;
    PlsrProfileQueue.writeIndex = 0U;
    PlsrProfileQueue.active = 0U;
    PlsrProfileQueue.generatorComplete = 0U;
    PlsrProfileQueue.producerEpoch = 0UL;
    PlsrProfileQueue.producerSegment = 0U;
    PlsrProfileQueue.preparedHandoffBank = 0U;
    PlsrProfileQueue.producerProfile.active = 0U;
    PlsrPlatformExitCritical(criticalState);
}

static uint8_t PlsrProfileQueueBegin(
    const PLSR_SHORT_PROFILE *producerProfile,
    uint32_t producerEpoch,
    uint8_t producerSegment,
    uint8_t preparedHandoffBank)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();

    PlsrProfileQueue.generation++;
    PlsrProfileQueue.readIndex = 0U;
    PlsrProfileQueue.writeIndex = 0U;
    PlsrProfileQueue.producerEpoch = producerEpoch;
    PlsrProfileQueue.producerSegment = producerSegment;
    PlsrProfileQueue.preparedHandoffBank = preparedHandoffBank;
    PlsrProfileQueue.generatorComplete = 0U;
    PlsrCopyShortProfile(&PlsrProfileQueue.producerProfile,
                         producerProfile);
    PlsrProfileQueue.active =
        ((producerProfile->active != 0U)
         && (producerProfile->nextPeriod < producerProfile->pulseCount))
            ? 1U : 0U;
    if (PlsrProfileQueue.active == 0U)
    {
        PlsrProfileQueue.generatorComplete = 1U;
    }
    PlsrPlatformExitCritical(criticalState);
    return 1U;
}

static void PlsrProfileQueueInvalidateGeneration(void)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();

    PlsrProfileQueue.generation++;
    PlsrProfileQueue.active = 0U;
    PlsrProfileQueue.generatorComplete = 0U;
    PlsrProfileQueue.readIndex = 0U;
    PlsrProfileQueue.writeIndex = 0U;
    PlsrPlatformExitCritical(criticalState);
}

#if defined(PLSR_DEBUG_TIMING) && (PLSR_DEBUG_TIMING != 0) \
    && !defined(PLSR_HOST_TEST)
static uint32_t PlsrProfileTimingNow(void)
{
    return *((volatile uint32_t *)0xE0001004UL);
}

static void PlsrProfileRecordProducerCycles(uint32_t startCycles)
{
    uint32_t elapsed = PlsrProfileTimingNow() - startCycles;
    uint32_t total = PlsrProfileProducerTotalCycles;

    if (PlsrProfileProducerItemCount != 0xFFFFFFFFUL)
    {
        PlsrProfileProducerItemCount++;
    }
    PlsrProfileProducerTotalCycles =
        (elapsed > (0xFFFFFFFFUL - total)) ? 0xFFFFFFFFUL
                                           : total + elapsed;
    if (elapsed > PlsrProfileProducerMaxItemCycles)
    {
        PlsrProfileProducerMaxItemCycles = elapsed;
    }
}
#endif

static uint8_t PlsrProfileQueueFill(uint16_t targetCount)
{
    PLSR_SHORT_PROFILE candidate;
    PLSR_PROFILE_ENTRY entry;
    uint32_t generation;
    uint32_t producerEpoch;
    uint32_t criticalState;
    uint32_t writeIndex;
#if defined(PLSR_DEBUG_TIMING) && (PLSR_DEBUG_TIMING != 0) \
    && !defined(PLSR_HOST_TEST)
    uint32_t startCycles;
#endif

    if ((targetCount == 0U)
        || (targetCount > PLSR_PROFILE_QUEUE_CAPACITY))
    {
        targetCount = PLSR_PROFILE_QUEUE_CAPACITY;
    }
    while (1)
    {
        criticalState = PlsrPlatformEnterCritical();
        if ((PlsrProfileQueue.active == 0U)
            || (PlsrProfileQueue.generatorComplete != 0U)
            || (PlsrProfileQueueCount() >= targetCount))
        {
            PlsrPlatformExitCritical(criticalState);
            return 1U;
        }
        generation = PlsrProfileQueue.generation;
        producerEpoch = PlsrProfileQueue.producerEpoch;
        PlsrCopyShortProfile(&candidate,
                             &PlsrProfileQueue.producerProfile);
        PlsrPlatformExitCritical(criticalState);

#if defined(PLSR_DEBUG_TIMING) && (PLSR_DEBUG_TIMING != 0) \
        && !defined(PLSR_HOST_TEST)
        startCycles = PlsrProfileTimingNow();
#endif
        entry.requestedFrequencyHz =
            PlsrShortProfileTakeFrequency(&candidate);
        if (PlsrPlatformBuildTimerSetting(
                (uint8_t)PlsrActiveConfig.pulseOutput,
                (uint8_t)PlsrActiveConfig.outputMode,
                entry.requestedFrequencyHz, &entry.setting) == 0U)
        {
            return 0U;
        }

        criticalState = PlsrPlatformEnterCritical();
        if ((PlsrProfileQueue.active == 0U)
            || (PlsrProfileQueue.generation != generation)
            || (PlsrProfileQueue.producerEpoch != producerEpoch)
            || (PlsrProfileQueueCount() >= PLSR_PROFILE_QUEUE_CAPACITY))
        {
            PlsrPlatformExitCritical(criticalState);
            continue;
        }
        writeIndex = PlsrProfileQueue.writeIndex;
        PlsrProfileQueue.entries[writeIndex & PLSR_PROFILE_QUEUE_MASK] = entry;
        PlsrCopyShortProfile(&PlsrProfileQueue.producerProfile, &candidate);
        PlsrProfileQueue.writeIndex = writeIndex + 1UL;
        if ((candidate.active == 0U)
            || (candidate.nextPeriod >= candidate.pulseCount))
        {
            PlsrProfileQueue.generatorComplete = 1U;
        }
        PlsrPlatformExitCritical(criticalState);
#if defined(PLSR_DEBUG_TIMING) && (PLSR_DEBUG_TIMING != 0) \
        && !defined(PLSR_HOST_TEST)
        PlsrProfileRecordProducerCycles(startCycles);
#endif
    }
}

static PLSR_PLATFORM_QUEUE_RESULT PlsrProfileQueueCommitNext(
    uint8_t pulseOutput)
{
    const PLSR_PROFILE_ENTRY *entry;
    uint32_t readIndex;
    uint32_t nextReadIndex;
    uint32_t writeIndex;
    uint32_t actualFrequencyHz;
    PLSR_PLATFORM_QUEUE_RESULT result;

    if (PlsrProfileQueue.active == 0U)
    {
        if (PlsrProfileQueue.generatorComplete != 0U)
        {
            PlsrShortProfile.active = 0U;
        }
        return PLSR_PLATFORM_QUEUE_APPLIED;
    }
    readIndex = PlsrProfileQueue.readIndex;
    if (readIndex == PlsrProfileQueue.writeIndex)
    {
        if (PlsrProfileQueue.generatorComplete != 0U)
        {
            PlsrProfileQueue.active = 0U;
            PlsrShortProfile.active = 0U;
            return PLSR_PLATFORM_QUEUE_APPLIED;
        }
        return PLSR_PLATFORM_QUEUE_FAILED;
    }

    entry = &PlsrProfileQueue.entries[readIndex & PLSR_PROFILE_QUEUE_MASK];
    result = PlsrPlatformLoadPreparedFromIrq(pulseOutput, &entry->setting,
                                              &actualFrequencyHz);
    if (result != PLSR_PLATFORM_QUEUE_APPLIED)
    {
        return result;
    }
    nextReadIndex = readIndex + 1UL;
    PlsrProfileQueue.readIndex = nextReadIndex;
    PlsrDeferredFrequencyPending = 0U;
    PlsrQueuedFrequencyHz = actualFrequencyHz;
    PlsrDiagnosticRecordFrequency(entry->requestedFrequencyHz,
                                  entry->setting.actualFrequencyHz,
                                  actualFrequencyHz);
    PlsrDiagnosticQueuedExpectedHz = entry->setting.actualFrequencyHz;
    if (actualFrequencyHz > PlsrCurrentFrequencyHz)
    {
        PlsrRunStatus = PLSR_STATUS_ACCELERATING;
    }
    else if (actualFrequencyHz < PlsrCurrentFrequencyHz)
    {
        PlsrRunStatus = PLSR_STATUS_DECELERATING;
    }
    else
    {
        PlsrRunStatus = PLSR_STATUS_RUNNING;
    }
    writeIndex = PlsrProfileQueue.writeIndex;
    if ((nextReadIndex == writeIndex)
        && (PlsrProfileQueue.generatorComplete != 0U))
    {
        PlsrProfileQueue.active = 0U;
        PlsrShortProfile.active = 0U;
    }
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

static void PlsrInvalidateHandoffPlans(void)
{
    uint8_t bank;
    uint8_t index;
    uint32_t criticalState = PlsrPlatformEnterCritical();

    PlsrHandoffPlan.valid = 0U;
    for (bank = 0U; bank < 2U; bank++)
    {
        for (index = 0U; index < PLSR_SEGMENT_COUNT_MAX; index++)
        {
            PlsrPreparedHandoffPlans[bank][index].valid = 0U;
        }
    }
    PlsrPlatformExitCritical(criticalState);
}

static void PlsrMaybePlanBoundaryRamp(uint32_t expectedEpoch)
{
    const PLSR_SEGMENT_CONFIG *segment;
    uint8_t nextSegment;
    uint8_t nextPositive;
    uint8_t hasNext;
    uint32_t targetHz;
    uint32_t criticalState;
    uint32_t currentHz;
    uint32_t queuedHz;
    uint32_t deferredHz;
    uint32_t rateBoundHz;
    uint8_t deferredPending;
    uint64_t estimate;
    uint64_t candidateEstimate;
    uint64_t remaining;
    uint8_t rampActive;

    if ((PlsrPulseActive == 0U)
        || (PlsrBoundaryRampStarted != 0U)
        || (PlsrShortProfile.active != 0U)
        || (PlsrHandoffPlan.valid != 0U)
        || (PlsrStopRequested != 0U) || (PlsrCurrentSegment == 0U))
    {
        return;
    }

    segment = &PlsrActiveConfig.segments[PlsrCurrentSegment - 1U];
    hasNext = PlsrGetNextSegment(&nextSegment);
    targetHz = PlsrEffectiveStopFrequency(segment->frequencyHz);

    if ((hasNext != 0U)
        && (segment->waitType == PLSR_EXT_OR_COMPLETE))
    {
        if ((PlsrPredictNextDirection(nextSegment, &nextPositive) != 0U)
            && (nextPositive == PlsrCountPositive))
        {
            targetHz = PlsrActiveConfig.segments[nextSegment - 1U].frequencyHz;
        }
    }

    criticalState = PlsrPlatformEnterCritical();
    currentHz = PlsrCurrentFrequencyHz;
    queuedHz = PlsrQueuedFrequencyHz;
    deferredHz = PlsrDeferredFrequencyHz;
    deferredPending = PlsrDeferredFrequencyPending;
    if ((PlsrSegmentEpoch != expectedEpoch)
        || (PlsrBoundaryPending != 0U)
        || (PlsrPulseActive == 0U)
        || (PlsrBoundaryRampStarted != 0U)
        || (PlsrShortProfile.active != 0U)
        || (PlsrHandoffPlan.valid != 0U)
        || (PlsrStopRequested != 0U)
        || (PlsrAbStopArmed != 0U))
    {
        PlsrPlatformExitCritical(criticalState);
        return;
    }
    PlsrPlatformExitCritical(criticalState);

    rateBoundHz = (currentHz > queuedHz) ? currentHz : queuedHz;
    if ((deferredPending != 0U) && (deferredHz > rateBoundHz))
    {
        rateBoundHz = deferredHz;
    }
    estimate = PlsrRampPulseEstimate(currentHz, targetHz, rateBoundHz);
    candidateEstimate = PlsrRampPulseEstimate(queuedHz, targetHz,
                                              rateBoundHz);
    if (candidateEstimate > estimate)
    {
        estimate = candidateEstimate;
    }
    if (deferredPending != 0U)
    {
        candidateEstimate = PlsrRampPulseEstimate(deferredHz, targetHz,
                                                  rateBoundHz);
        if (candidateEstimate > estimate)
        {
            estimate = candidateEstimate;
        }
    }

    criticalState = PlsrPlatformEnterCritical();
    remaining = PlsrRemainingPulses;
    if ((PlsrSegmentEpoch != expectedEpoch)
        || (PlsrBoundaryPending != 0U)
        || (PlsrPulseActive == 0U)
        || (PlsrBoundaryRampStarted != 0U)
        || (PlsrShortProfile.active != 0U)
        || (PlsrHandoffPlan.valid != 0U)
        || (PlsrStopRequested != 0U)
        || (PlsrAbStopArmed != 0U))
    {
        PlsrPlatformExitCritical(criticalState);
        return;
    }
    if (remaining > estimate)
    {
        PlsrPlatformExitCritical(criticalState);
        return;
    }

    PlsrBoundaryRampStarted = 1U;
    PlsrRampStart(PlsrCurrentFrequencyHz, targetHz);
    rampActive = PlsrRamp.active;
    PlsrPlatformExitCritical(criticalState);
    if (rampActive != 0U)
    {
        if (PlsrRampAdvance(expectedEpoch) == 0U)
        {
            PlsrEnterErrorIfEpoch(PLSR_ERROR_TIMER, expectedEpoch);
        }
    }
    else
    {
        (void)PlsrApplyFrequency(targetHz, expectedEpoch);
    }
}


static uint8_t PlsrBeginSegmentOutput(uint32_t startFrequencyHz)
{
    uint32_t targetFrequencyHz =
        PlsrActiveConfig.segments[PlsrCurrentSegment - 1U].frequencyHz;
    uint32_t firstFrequencyHz;
    uint32_t secondFrequencyHz;
    uint32_t profileEpoch;
    uint8_t profileSegment;
    uint8_t profileHandoffBank;

    PlsrSegmentClockStarted = 1U;
    PlsrSegmentElapsedMs = 0UL;
    if (PlsrPrepareShortProfile(&PlsrShortProfile,
                                PlsrCurrentSegment, startFrequencyHz,
                                targetFrequencyHz,
                                PlsrRemainingSnapshot()) != 0U)
    {
        PlsrRamp.active = 0U;
        PlsrRefreshCurrentHandoffPlan(PlsrShortProfile.endHz);
        firstFrequencyHz =
            PlsrShortProfileTakeFrequency(&PlsrShortProfile);
        secondFrequencyHz =
            (PlsrShortProfile.nextPeriod < PlsrShortProfile.pulseCount)
                ? PlsrShortProfileTakeFrequency(&PlsrShortProfile)
                : firstFrequencyHz;
        profileEpoch = PlsrSegmentEpoch;
        profileSegment = PlsrCurrentSegment;
        profileHandoffBank = PlsrPreparedHandoffBank;
        (void)PlsrProfileQueueBegin(&PlsrShortProfile,
                                    profileEpoch,
                                    profileSegment,
                                    profileHandoffBank);
        if (PlsrProfileQueueFill(PLSR_PROFILE_QUEUE_CAPACITY) == 0U)
        {
            PlsrProfileQueueReset();
            PlsrShortProfile.active = 0U;
            return 0U;
        }
        if (secondFrequencyHz > firstFrequencyHz)
        {
            PlsrRunStatus = PLSR_STATUS_ACCELERATING;
        }
        else if (secondFrequencyHz < firstFrequencyHz)
        {
            PlsrRunStatus = PLSR_STATUS_DECELERATING;
        }
        else
        {
            PlsrRunStatus = PLSR_STATUS_RUNNING;
        }
        if (PlsrApplyFrequencyPair(firstFrequencyHz,
                                   secondFrequencyHz,
                                   PlsrSegmentEpoch) == 0U)
        {
            PlsrProfileQueueReset();
            PlsrShortProfile.active = 0U;
            return 0U;
        }
        PlsrExecutor.generation++;
        PlsrExecutor.mode = PLSR_EXEC_STREAM;
        return 1U;
    }

    if (PlsrActiveConfig.outputMode == PLSR_OUTPUT_PULSE_DIR)
    {
        return 0U;
    }

    PlsrProfileQueueReset();

    PlsrRampStart(startFrequencyHz, targetFrequencyHz);

    if (PlsrRamp.active == 0U)
    {
        if (PlsrApplyFrequency(targetFrequencyHz, PlsrSegmentEpoch) == 0U)
        {
            return 0U;
        }
        PlsrRunStatus = PLSR_STATUS_RUNNING;
    }
    else if ((startFrequencyHz != 0UL)
             && (PlsrApplyFrequency(startFrequencyHz,
                                    PlsrSegmentEpoch) == 0U))
    {
        return 0U;
    }
    if (PlsrPrepareFutureHandoffQueue() == 0U)
    {
        return 0U;
    }
    PlsrExecutor.generation++;
    PlsrExecutor.mode = PLSR_EXEC_AB_LEGACY;
    return 1U;
}

static uint8_t PlsrStartSegment(uint8_t segmentNumber,
                                uint8_t allowCarry,
                                uint32_t carryFrequencyHz)
{
    uint32_t criticalState;
    int32_t position;
    int64_t displacement;
    uint64_t magnitude;
    uint8_t positive;
    uint8_t directionLevel;
    uint8_t directionChanged;
    uint32_t startFrequencyHz;

    if ((segmentNumber == 0U)
        || (segmentNumber > PlsrActiveConfig.segmentCount))
    {
        return 0U;
    }

    criticalState = PlsrPlatformEnterCritical();
    position = PlsrPosition;
    PlsrPlatformExitCritical(criticalState);
    displacement = PlsrSegmentDisplacement(segmentNumber, position);
    positive = (displacement >= 0) ? 1U : 0U;
    magnitude = (displacement < 0) ? (uint64_t)(-displacement)
                                   : (uint64_t)displacement;

    PlsrSegmentEpoch++;
    PlsrCurrentSegment = segmentNumber;
    PlsrSegmentClockStarted = 0U;
    PlsrSegmentElapsedMs = 0UL;
    PlsrWaitElapsedMs = 0UL;
    PlsrBoundaryRampStarted = 0U;
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrCutRequested = 0U;
    PlsrStopPulsesRemaining = 0U;
    PlsrAbStopArmed = 0U;
    PlsrFrequencyUpdatePending = 0U;
    PlsrDeferredFrequencyPending = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrHandoffPlan.valid = 0U;
    PlsrShortProfile.active = 0U;
    PlsrShortProfile.nextPeriod = 0U;
    if ((allowCarry == 0U) || (PlsrProfileQueue.active == 0U)
        || (PlsrProfileQueue.producerEpoch != PlsrSegmentEpoch)
        || (PlsrProfileQueue.producerSegment != segmentNumber))
    {
        PlsrProfileQueueReset();
    }
    PlsrDirectionDelayActive = 0U;
    PlsrDirectionDelayRemainingMs = 0U;
    PlsrExtEdgePending = 0U;
    PlsrExtPreviousLevel =
        PlsrPlatformReadInput((uint8_t)PlsrActiveConfig.extInput);

    criticalState = PlsrPlatformEnterCritical();
    PlsrRemainingPulses = magnitude;
    PlsrCountPositive = positive;
    PlsrPlatformExitCritical(criticalState);

    if ((PlsrActiveConfig.segments[segmentNumber - 1U].waitType
         == PLSR_ACT_TIME)
        && (PlsrActiveConfig.segments[segmentNumber - 1U].actTimeMs == 0U))
    {
        PlsrSegmentClockStarted = 1U;
        PlsrRunStatus = PLSR_STATUS_RUNNING;
        PlsrBoundaryFrequencyHz = (allowCarry != 0U) ? carryFrequencyHz : 0UL;
        PlsrBoundaryWasCut = 1U;
        PlsrBoundaryPending = 1U;
        PlsrDiagnosticBeginSegment(segmentNumber, 0UL, positive);
        PlsrDiagnosticFinishSegment(1U);
        return 1U;
    }

    if (magnitude == 0UL)
    {
        PlsrSegmentClockStarted = 1U;
        PlsrRunStatus = PLSR_STATUS_RUNNING;
        PlsrBoundaryFrequencyHz = 0UL;
        PlsrBoundaryPending = 1U;
        PlsrDiagnosticBeginSegment(segmentNumber, 0UL, positive);
        PlsrDiagnosticFinishSegment(1U);
        return 1U;
    }

    directionLevel = positive;
    if ((PlsrActiveConfig.outputMode == PLSR_OUTPUT_PULSE_DIR)
        && (PlsrActiveConfig.directionNegativeLogic != 0U))
    {
        directionLevel ^= 1U;
    }
    directionChanged = ((PlsrLastDirectionValid == 0U)
                        || (PlsrLastDirectionOutput
                            != (uint8_t)PlsrActiveConfig.directionOutput)
                        || (PlsrLastDirectionLevel != directionLevel)) ? 1U : 0U;

    if (PlsrPlatformPrepare((uint8_t)PlsrActiveConfig.pulseOutput,
                            (uint8_t)PlsrActiveConfig.directionOutput,
                            directionLevel,
                            (uint8_t)PlsrActiveConfig.outputMode,
                            positive) == 0U)
    {
        return 0U;
    }
    PlsrDiagnosticBeginSegment(segmentNumber, magnitude, positive);
    PlsrLastDirectionValid = 1U;
    PlsrLastDirectionOutput = (uint8_t)PlsrActiveConfig.directionOutput;
    PlsrLastDirectionLevel = directionLevel;

    startFrequencyHz = PlsrEffectiveStartFrequency(
        PlsrActiveConfig.segments[segmentNumber - 1U].frequencyHz,
        allowCarry, directionChanged, carryFrequencyHz);

    if ((PlsrActiveConfig.outputMode == PLSR_OUTPUT_PULSE_DIR)
        && (directionChanged != 0U)
        && (PlsrActiveConfig.directionDelayMs != 0U))
    {
        PlsrDirectionDelayActive = 1U;
        PlsrDirectionDelayRemainingMs = PlsrActiveConfig.directionDelayMs;
        PlsrRunStatus = PLSR_STATUS_ACCELERATING;
        return 1U;
    }

    PlsrDirectionDelayActive = 0U;
    return PlsrBeginSegmentOutput(startFrequencyHz);
}

static void PlsrMarkPersistenceDirty(uint16_t delayMs)
{
    PlsrPersistenceDirty = 1U;
    PlsrPersistenceDelayMs = delayMs;
}

static void PlsrCheckpointPosition(uint8_t wasBusy)
{
    uint32_t criticalState;
    int32_t position;
    uint8_t positionValid;

    criticalState = PlsrPlatformEnterCritical();
    position = PlsrPosition;
    positionValid = PlsrPositionValid;
    PlsrPositionCheckpointDirty = 0U;
    PlsrPlatformExitCritical(criticalState);
    PlsrPlatformCheckpointPosition(position, positionValid, wasBusy);
    PlsrPositionCheckpointElapsedMs = 0U;
}

static void PlsrPollPositionCheckpoint(void)
{
    if (PlsrPositionCheckpointDirty == 0U)
    {
        PlsrPositionCheckpointElapsedMs = 0U;
        return;
    }
    if (PlsrPositionCheckpointElapsedMs < PLSR_POSITION_CHECKPOINT_MS)
    {
        PlsrPositionCheckpointElapsedMs++;
    }
    if (PlsrPositionCheckpointElapsedMs >= PLSR_POSITION_CHECKPOINT_MS)
    {
        PlsrCheckpointPosition(1U);
    }
}

static void PlsrFinishCompleted(void)
{
    PlsrPlatformStopPulse((uint8_t)PlsrActiveConfig.pulseOutput);
    PlsrRemainingPulses = 0UL;
    PlsrPulseActive = 0U;
    PlsrCutRequested = 0U;
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrCurrentSegment = 0U;
    PlsrSegmentClockStarted = 0U;
    PlsrDirectionDelayActive = 0U;
    PlsrDirectionDelayRemainingMs = 0U;
    PlsrExtEdgePending = 0U;
    PlsrStopRequested = 0U;
    PlsrStopPulsesRemaining = 0U;
    PlsrAbStopArmed = 0U;
    PlsrSeamlessHandoffPending = 0U;
    PlsrDeferredFrequencyPending = 0U;
    PlsrShortProfile.active = 0U;
    PlsrProfileQueueReset();
    PlsrHandoffPlan.valid = 0U;
    PlsrTimerErrorPending = 0U;
    PlsrRamp.active = 0U;
    PlsrExecutor.mode = PLSR_EXEC_IDLE;
    PlsrInvalidateHandoffPlans();
    PlsrRunStatus = PLSR_STATUS_COMPLETED;
    PlsrError = PLSR_ERROR_NONE;
    PlsrCheckpointPosition(0U);
    PlsrMarkPersistenceDirty(PLSR_CONFIG_SAVE_DELAY_MS);
}

static void PlsrFinishStopped(void)
{
    PlsrDiagnosticFinishSegment(0U);
    PlsrPlatformStopPulse((uint8_t)PlsrActiveConfig.pulseOutput);
    PlsrRemainingPulses = 0UL;
    PlsrPulseActive = 0U;
    PlsrCutRequested = 0U;
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrCurrentSegment = 0U;
    PlsrSegmentClockStarted = 0U;
    PlsrDirectionDelayActive = 0U;
    PlsrDirectionDelayRemainingMs = 0U;
    PlsrExtEdgePending = 0U;
    PlsrStopRequested = 0U;
    PlsrStopPulsesRemaining = 0U;
    PlsrAbStopArmed = 0U;
    PlsrSeamlessHandoffPending = 0U;
    PlsrDeferredFrequencyPending = 0U;
    PlsrShortProfile.active = 0U;
    PlsrProfileQueueReset();
    PlsrHandoffPlan.valid = 0U;
    PlsrTimerErrorPending = 0U;
    PlsrRamp.active = 0U;
    PlsrExecutor.mode = PLSR_EXEC_IDLE;
    PlsrInvalidateHandoffPlans();
    PlsrRunStatus = PLSR_STATUS_STOPPED;
    PlsrError = PLSR_ERROR_NONE;
    PlsrCheckpointPosition(0U);
    PlsrMarkPersistenceDirty(PLSR_CONFIG_SAVE_DELAY_MS);
}

static void PlsrEnterError(PLSR_ERROR error)
{
    PlsrDiagnosticFinishSegment(0U);
    PlsrPlatformStopPulse((uint8_t)PlsrActiveConfig.pulseOutput);
    PlsrRemainingPulses = 0UL;
    PlsrPulseActive = 0U;
    PlsrCutRequested = 0U;
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrCurrentSegment = 0U;
    PlsrSegmentClockStarted = 0U;
    PlsrDirectionDelayActive = 0U;
    PlsrDirectionDelayRemainingMs = 0U;
    PlsrExtEdgePending = 0U;
    PlsrStopRequested = 0U;
    PlsrStopPulsesRemaining = 0U;
    PlsrAbStopArmed = 0U;
    PlsrSeamlessHandoffPending = 0U;
    PlsrDeferredFrequencyPending = 0U;
    PlsrShortProfile.active = 0U;
    PlsrProfileQueueReset();
    PlsrHandoffPlan.valid = 0U;
    PlsrTimerErrorPending = 0U;
    PlsrRamp.active = 0U;
    PlsrExecutor.mode = PLSR_EXEC_IDLE;
    PlsrInvalidateHandoffPlans();
    PlsrRunStatus = PLSR_STATUS_ERROR;
    PlsrError = error;
    PlsrCheckpointPosition(0U);
    PlsrMarkPersistenceDirty(PLSR_CONFIG_SAVE_DELAY_MS);
}

static void PlsrTransitionToNext(uint8_t allowCarry)
{
    uint8_t nextSegment;
    uint32_t carryFrequencyHz = PlsrBoundaryFrequencyHz;

    if (PlsrGetNextSegment(&nextSegment) == 0U)
    {
        PlsrFinishCompleted();
        return;
    }

    if (PlsrStartSegment(nextSegment, allowCarry, carryFrequencyHz) == 0U)
    {
        PlsrEnterError(PLSR_ERROR_INVALID_RESOURCE);
    }
}

static uint8_t PlsrBuildHandoffPlan(uint8_t sourceSegment,
                                    const PLSR_CONFIG *frequencyConfig,
                                    uint32_t carryFrequencyHz,
                                    PLSR_HANDOFF_PLAN *plan)
{
    const PLSR_SEGMENT_CONFIG *segment;
    uint8_t nextSegment;
    int64_t displacement;
    uint32_t nextFrequencyHz;
    uint8_t positive;
    uint8_t warmupIndex;

    plan->valid = 0U;
    if ((sourceSegment == 0U)
        || (sourceSegment > PlsrActiveConfig.segmentCount))
    {
        return 0U;
    }

    segment = &PlsrActiveConfig.segments[sourceSegment - 1U];
    if (segment->waitType != PLSR_EXT_OR_COMPLETE)
    {
        return 0U;
    }
    if (segment->jumpSegment != 0U)
    {
        nextSegment = (uint8_t)segment->jumpSegment;
    }
    else if (sourceSegment < PlsrActiveConfig.segmentCount)
    {
        nextSegment = (uint8_t)(sourceSegment + 1U);
    }
    else
    {
        return 0U;
    }

    if (PlsrActiveConfig.positionMode == PLSR_POSITION_ABSOLUTE)
    {
        displacement = (int64_t)PlsrActiveConfig.segments[nextSegment - 1U].pulses
                       - (int64_t)segment->pulses;
    }
    else
    {
        displacement = PlsrActiveConfig.segments[nextSegment - 1U].pulses;
    }
    if (displacement == 0)
    {
        return 0U;
    }
    positive = (displacement > 0) ? 1U : 0U;

    plan->magnitude = (displacement < 0) ? (uint64_t)(-displacement)
                                         : (uint64_t)displacement;
    if (carryFrequencyHz == 0UL)
    {
        carryFrequencyHz =
            PlsrResolvedSegmentFrequency(frequencyConfig, sourceSegment - 1U);
    }
    nextFrequencyHz =
        PlsrResolvedSegmentFrequency(frequencyConfig, nextSegment - 1U);
    if (PlsrPrepareShortProfile(&plan->profile, nextSegment,
                                carryFrequencyHz, nextFrequencyHz,
                                plan->magnitude) == 0U)
    {
        return 0U;
    }
    plan->firstFrequencyHz =
        PlsrShortProfileTakeFrequency(&plan->profile);
    plan->secondFrequencyHz =
        (plan->profile.nextPeriod < plan->profile.pulseCount)
            ? PlsrShortProfileTakeFrequency(&plan->profile)
            : plan->firstFrequencyHz;
    plan->firstRequestedFrequencyHz = plan->firstFrequencyHz;
    plan->secondRequestedFrequencyHz = plan->secondFrequencyHz;
    if ((PlsrPlatformBuildTimerSetting(
             (uint8_t)PlsrActiveConfig.pulseOutput,
             (uint8_t)PlsrActiveConfig.outputMode,
             plan->firstFrequencyHz, &plan->firstSetting) == 0U)
        || (PlsrPlatformBuildTimerSetting(
                (uint8_t)PlsrActiveConfig.pulseOutput,
                (uint8_t)PlsrActiveConfig.outputMode,
                plan->secondFrequencyHz, &plan->secondSetting) == 0U))
    {
        return 0U;
    }
    plan->warmupCount = 0U;
    for (warmupIndex = 0U;
         (warmupIndex < PLSR_HANDOFF_WARMUP_ITEMS)
         && (plan->profile.nextPeriod < plan->profile.pulseCount);
         warmupIndex++)
    {
        PLSR_PROFILE_ENTRY *entry = &plan->warmup[warmupIndex];

        entry->requestedFrequencyHz =
            PlsrShortProfileTakeFrequency(&plan->profile);
        if (PlsrPlatformBuildTimerSetting(
                (uint8_t)PlsrActiveConfig.pulseOutput,
                (uint8_t)PlsrActiveConfig.outputMode,
                entry->requestedFrequencyHz, &entry->setting) == 0U)
        {
            return 0U;
        }
        plan->warmupCount++;
    }
    plan->firstFrequencyHz = plan->firstSetting.actualFrequencyHz;
    plan->secondFrequencyHz = plan->secondSetting.actualFrequencyHz;
    plan->nextSegment = nextSegment;
    plan->positive = positive;
    plan->valid = 1U;
    return 1U;
}

static uint8_t PlsrBuildHandoffPlanBank(
    const PLSR_CONFIG *frequencyConfig)
{
    uint8_t buildBank = (uint8_t)(PlsrPreparedHandoffBank ^ 1U);
    uint8_t sourceSegment;
    PLSR_HANDOFF_PLAN *destination;

    for (sourceSegment = 0U;
         sourceSegment < PLSR_SEGMENT_COUNT_MAX;
         sourceSegment++)
    {
        PlsrPreparedHandoffPlans[buildBank][sourceSegment].valid = 0U;
    }
    for (sourceSegment = 1U;
         sourceSegment <= PlsrActiveConfig.segmentCount;
         sourceSegment++)
    {
        destination =
            &PlsrPreparedHandoffPlans[buildBank][sourceSegment - 1U];
        (void)PlsrBuildHandoffPlan(sourceSegment, frequencyConfig, 0UL,
                                   destination);
    }
    return buildBank;
}

static void PlsrRefreshCurrentHandoffPlan(uint32_t terminalFrequencyHz)
{
    PLSR_PLATFORM_TIMER_SETTING terminalSetting;
    PLSR_HANDOFF_PLAN *destination;
    uint8_t currentSegment = PlsrCurrentSegment;
    uint8_t preparedBank = PlsrPreparedHandoffBank;

    if ((currentSegment == 0U)
        || (currentSegment > PlsrActiveConfig.segmentCount)
        || (PlsrPlatformBuildTimerSetting(
                (uint8_t)PlsrActiveConfig.pulseOutput,
                (uint8_t)PlsrActiveConfig.outputMode,
                terminalFrequencyHz, &terminalSetting) == 0U))
    {
        return;
    }
    destination = &PlsrPreparedHandoffPlans[preparedBank]
                                               [currentSegment - 1U];
    (void)PlsrBuildHandoffPlan(currentSegment, &PlsrActiveConfig,
                               terminalSetting.actualFrequencyHz,
                               destination);
}

static uint8_t PlsrSelectPreparedHandoffPlan(PLSR_HANDOFF_PLAN *plan)
{
    const PLSR_HANDOFF_PLAN *prepared;
    uint8_t preparedBank;
    uint8_t currentSegment;

    plan->valid = 0U;
    currentSegment = PlsrCurrentSegment;
    if ((PlsrRemainingPulses != 1UL)
        || (PlsrStopRequested != 0U)
        || (PlsrCountOverflowPending != 0U)
        || (PlsrCutRequested != 0U)
        || (PlsrAbStopArmed != 0U)
        || (currentSegment == 0U)
        || (currentSegment > PlsrActiveConfig.segmentCount))
    {
        return 0U;
    }
    preparedBank = PlsrPreparedHandoffBank;
    prepared = &PlsrPreparedHandoffPlans[preparedBank][currentSegment - 1U];
    if ((prepared->valid == 0U)
        || (prepared->positive != PlsrCountPositive))
    {
        return 0U;
    }

    *plan = *prepared;
    return 1U;
}

static uint8_t PlsrPrepareFutureHandoffQueue(void)
{
    const PLSR_HANDOFF_PLAN *prepared;
    uint8_t currentSegment = PlsrCurrentSegment;
    uint8_t preparedBank = PlsrPreparedHandoffBank;

    PlsrProfileQueueReset();
    if ((currentSegment == 0U)
        || (currentSegment > PlsrActiveConfig.segmentCount))
    {
        return 1U;
    }
    prepared = &PlsrPreparedHandoffPlans[preparedBank][currentSegment - 1U];
    if ((prepared->valid == 0U) || (prepared->profile.active == 0U)
        || (prepared->profile.nextPeriod >= prepared->profile.pulseCount))
    {
        return 1U;
    }
    (void)PlsrProfileQueueBegin(&prepared->profile,
                                PlsrSegmentEpoch + 1UL,
                                prepared->nextSegment,
                                preparedBank);
    if (PlsrProfileQueueFill(PLSR_PROFILE_QUEUE_CAPACITY) == 0U)
    {
        PlsrProfileQueueReset();
        return 0U;
    }
    return 1U;
}

/* The first two periods are already in the timer pipeline.  Seed a small
   precomputed tail here so the 1 ms producer has time to resume without
   doing planner math in the pulse IRQ. */
static void PlsrActivateHandoffQueueFromIrq(
    const PLSR_HANDOFF_PLAN *plan,
    uint32_t producerEpoch)
{
    uint8_t index;

    PlsrProfileQueue.generation++;
    PlsrProfileQueue.readIndex = 0U;
    PlsrProfileQueue.writeIndex = plan->warmupCount;
    for (index = 0U; index < plan->warmupCount; index++)
    {
        PlsrProfileQueue.entries[index] = plan->warmup[index];
    }
    PlsrCopyShortProfile(&PlsrProfileQueue.producerProfile,
                         &plan->profile);
    PlsrProfileQueue.producerEpoch = producerEpoch;
    PlsrProfileQueue.producerSegment = plan->nextSegment;
    PlsrProfileQueue.preparedHandoffBank = PlsrPreparedHandoffBank;
    PlsrProfileQueue.generatorComplete =
        (plan->profile.active == 0U) ? 1U : 0U;
    PlsrProfileQueue.active =
        ((plan->warmupCount != 0U) || (plan->profile.active != 0U))
            ? 1U : 0U;
    PlsrCopyShortProfile(&PlsrShortProfile, &plan->profile);
    if (PlsrProfileQueue.active != 0U)
    {
        PlsrShortProfile.active = 1U;
    }
}

static PLSR_PLATFORM_QUEUE_RESULT PlsrPrimeHandoff(void)
{
    PLSR_HANDOFF_PLAN candidatePlan;
    uint32_t actualFrequencyHz;
    PLSR_PLATFORM_QUEUE_RESULT result;

    PlsrHandoffPlan.valid = 0U;
    if (PlsrAbStopArmed != 0U)
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if (PlsrSelectPreparedHandoffPlan(&candidatePlan) == 0U)
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    PlsrDeferredFrequencyPending = 0U;
    result = PlsrPlatformLoadPreparedFromIrq(
        (uint8_t)PlsrActiveConfig.pulseOutput,
        &candidatePlan.firstSetting, &actualFrequencyHz);
    if (result != PLSR_PLATFORM_QUEUE_APPLIED)
    {
        if (result == PLSR_PLATFORM_QUEUE_FAILED)
        {
            PlsrTimerErrorPending = 1U;
        }
        return result;
    }

    PlsrDiagnosticRecordFrequency(candidatePlan.firstRequestedFrequencyHz,
                                  candidatePlan.firstSetting.actualFrequencyHz,
                                  actualFrequencyHz);
    PlsrDiagnosticQueuedExpectedHz =
        candidatePlan.firstSetting.actualFrequencyHz;
    PlsrQueuedFrequencyHz = actualFrequencyHz;
    PlsrHandoffPlan = candidatePlan;
    PlsrHandoffPlan.firstFrequencyHz = actualFrequencyHz;
    PlsrHandoffPlan.valid = 1U;
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

static PLSR_PLATFORM_QUEUE_RESULT PlsrTryContinuousHandoff(void)
{
    uint32_t actualQueuedFrequencyHz;
    uint32_t currentFrequencyHz;
    uint32_t queuedFrequencyHz;
    uint8_t nextSegment = PlsrHandoffPlan.nextSegment;
    uint64_t magnitude = PlsrHandoffPlan.magnitude;
    uint8_t positive = PlsrHandoffPlan.positive;
    PLSR_PLATFORM_QUEUE_RESULT result;

    if ((PlsrHandoffPlan.valid == 0U)
        || (PlsrStopRequested != 0U)
        || (PlsrCountOverflowPending != 0U)
        || (PlsrCutRequested != 0U)
        || (PlsrAbStopArmed != 0U)
        || (PlsrCurrentFrequencyHz != PlsrHandoffPlan.firstFrequencyHz)
        || (nextSegment == 0U)
        || (nextSegment > PlsrActiveConfig.segmentCount))
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    PlsrDeferredFrequencyPending = 0U;
    result = PlsrPlatformLoadPreparedFromIrq(
        (uint8_t)PlsrActiveConfig.pulseOutput,
        &PlsrHandoffPlan.secondSetting, &actualQueuedFrequencyHz);
    if (result == PLSR_PLATFORM_QUEUE_STALE)
    {
        return result;
    }
    if (result == PLSR_PLATFORM_QUEUE_FAILED)
    {
        PlsrShortProfile.active = 0U;
        PlsrHandoffPlan.valid = 0U;
        PlsrTimerErrorPending = 1U;
        return result;
    }

    PlsrDiagnosticRecordFrequency(
        PlsrHandoffPlan.secondRequestedFrequencyHz,
        PlsrHandoffPlan.secondSetting.actualFrequencyHz,
        actualQueuedFrequencyHz);
    PlsrDiagnosticQueuedExpectedHz =
        PlsrHandoffPlan.secondSetting.actualFrequencyHz;
    PlsrQueuedFrequencyHz = actualQueuedFrequencyHz;
    PlsrDiagnosticFinishSegment(1U);
    PlsrSegmentEpoch++;
    PlsrActivateHandoffQueueFromIrq(&PlsrHandoffPlan,
                                    PlsrSegmentEpoch);
    PlsrCurrentSegment = nextSegment;
    PlsrRemainingPulses = magnitude;
    PlsrCountPositive = positive;
    PlsrBoundaryFrequencyHz = PlsrCurrentFrequencyHz;
    PlsrSegmentClockStarted = 1U;
    PlsrSegmentElapsedMs = 0UL;
    PlsrWaitElapsedMs = 0UL;
    PlsrBoundaryRampStarted = 0U;
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrCutRequested = 0U;
    PlsrFrequencyUpdatePending = 0U;
    PlsrDeferredFrequencyPending = 0U;
    PlsrExtEdgePending = 0U;
    PlsrExtPreviousLevel =
        PlsrPlatformReadInput((uint8_t)PlsrActiveConfig.extInput);
    PlsrDiagnosticBeginSegment(nextSegment, magnitude, positive);
    PlsrSeamlessHandoffPending = 1U;
    PlsrHandoffPlan.valid = 0U;
    if (PlsrRemainingPulses == 1UL)
    {
        result = PlsrPrimeHandoff();
        if (result == PLSR_PLATFORM_QUEUE_STALE)
        {
            return result;
        }
    }
    (void)PlsrQueueFinalAbBoundaryFromIrq();
    queuedFrequencyHz = PlsrQueuedFrequencyHz;
    currentFrequencyHz = PlsrCurrentFrequencyHz;
    if (PlsrShortProfile.active != 0U)
    {
        if (queuedFrequencyHz > currentFrequencyHz)
        {
            PlsrRunStatus = PLSR_STATUS_ACCELERATING;
        }
        else if (queuedFrequencyHz < currentFrequencyHz)
        {
            PlsrRunStatus = PLSR_STATUS_DECELERATING;
        }
        else
        {
            PlsrRunStatus = PLSR_STATUS_RUNNING;
        }
    }
    else
    {
        PlsrRunStatus = PLSR_STATUS_RUNNING;
    }
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

static void PlsrHandleBoundary(uint8_t extEdge)
{
    const PLSR_SEGMENT_CONFIG *segment;
    uint8_t wasCut = PlsrBoundaryWasCut;

    PlsrPlatformStopPulse((uint8_t)PlsrActiveConfig.pulseOutput);
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrPulseActive = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrShortProfile.active = 0U;
    PlsrProfileQueueReset();
    PlsrHandoffPlan.valid = 0U;
    PlsrDeferredFrequencyPending = 0U;
    PlsrAbStopArmed = 0U;
    PlsrCheckpointPosition(1U);

    if (PlsrTimerErrorPending != 0U)
    {
        PlsrTimerErrorPending = 0U;
        PlsrEnterError(PLSR_ERROR_TIMER);
        return;
    }
    if (PlsrCountOverflowPending != 0U)
    {
        PlsrCountOverflowPending = 0U;
        PlsrEnterError(PLSR_ERROR_COUNT);
        return;
    }

    if (PlsrStopRequested != 0U)
    {
        PlsrFinishStopped();
        return;
    }
    if ((PlsrCurrentSegment == 0U)
        || (PlsrCurrentSegment > PlsrActiveConfig.segmentCount))
    {
        PlsrEnterError(PLSR_ERROR_INTERNAL);
        return;
    }

    segment = &PlsrActiveConfig.segments[PlsrCurrentSegment - 1U];
    if (wasCut != 0U)
    {
        PlsrTransitionToNext(
            (PlsrActiveConfig.sendMode == PLSR_SEND_SUBSEQUENT) ? 1U : 0U);
        return;
    }

    switch (segment->waitType)
    {
        case PLSR_WAIT_TIME:
            PlsrWaitElapsedMs = 0UL;
            PlsrRunStatus = PLSR_STATUS_WAITING;
            break;

        case PLSR_WAIT_SIGNAL:
            if (PlsrPlatformReadInput((uint8_t)PlsrActiveConfig.waitInput) != 0U)
            {
                PlsrTransitionToNext(0U);
            }
            else
            {
                PlsrRunStatus = PLSR_STATUS_WAITING;
            }
            break;

        case PLSR_ACT_TIME:
            if (PlsrSegmentElapsedMs >= segment->actTimeMs)
            {
                PlsrTransitionToNext(0U);
            }
            else
            {
                PlsrRunStatus = PLSR_STATUS_WAITING;
            }
            break;

        case PLSR_EXT_SIGNAL:
            if (extEdge != 0U)
            {
                PlsrTransitionToNext(0U);
            }
            else
            {
                PlsrRunStatus = PLSR_STATUS_WAITING;
            }
            break;

        case PLSR_EXT_OR_COMPLETE:
            PlsrTransitionToNext(1U);
            break;

        default:
            PlsrEnterError(PLSR_ERROR_INTERNAL);
            break;
    }
}

static void PlsrRequestCut(uint32_t expectedEpoch)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();

    if (PlsrSegmentEpoch != expectedEpoch)
    {
        PlsrPlatformExitCritical(criticalState);
        return;
    }
    if (PlsrBoundaryPending != 0U)
    {
        PlsrBoundaryWasCut = 1U;
    }
    else if (PlsrPulseActive != 0U)
    {
        PlsrCutRequested = 1U;
        (void)PlsrArmFinalAbBoundaryLocked();
    }
    else
    {
        PlsrBoundaryFrequencyHz = PlsrCurrentFrequencyHz;
        PlsrBoundaryWasCut = 1U;
        PlsrBoundaryPending = 1U;
    }
    PlsrPlatformExitCritical(criticalState);
}

static void PlsrPollWaiting(uint8_t extEdge)
{
    const PLSR_SEGMENT_CONFIG *segment =
        &PlsrActiveConfig.segments[PlsrCurrentSegment - 1U];

    switch (segment->waitType)
    {
        case PLSR_WAIT_TIME:
            PlsrWaitElapsedMs++;
            if (PlsrWaitElapsedMs >= segment->waitTimeMs)
            {
                PlsrTransitionToNext(0U);
            }
            break;
        case PLSR_WAIT_SIGNAL:
            if (PlsrPlatformReadInput((uint8_t)PlsrActiveConfig.waitInput) != 0U)
            {
                PlsrTransitionToNext(0U);
            }
            break;
        case PLSR_ACT_TIME:
            if (PlsrSegmentElapsedMs >= segment->actTimeMs)
            {
                PlsrTransitionToNext(0U);
            }
            break;
        case PLSR_EXT_SIGNAL:
            if (extEdge != 0U)
            {
                PlsrTransitionToNext(0U);
            }
            break;
        default:
            PlsrEnterError(PLSR_ERROR_INTERNAL);
            break;
    }
}

static void PlsrPollPersistenceDelay(void)
{
    if ((PlsrPersistenceDirty != 0U)
        && (PlsrIsBusy() == 0U)
        && (PlsrPersistenceDelayMs != 0U))
    {
        PlsrPersistenceDelayMs--;
    }
}

void PlsrServicePersistence(void)
{
    PLSR_PERSIST_PAYLOAD payload;
    PLSR_PLATFORM_SERVICE_RESULT serviceResult;
    uint32_t criticalState;

    if (PlsrIsBusy() != 0U)
    {
        return;
    }
    serviceResult = PlsrPlatformServicePersistence();
    if (serviceResult == PLSR_PLATFORM_SERVICE_FAILED)
    {
        PlsrRunStatus = PLSR_STATUS_ERROR;
        PlsrError = PLSR_ERROR_INTERNAL;
        return;
    }
    if ((serviceResult == PLSR_PLATFORM_SERVICE_DEFERRED)
        || (PlsrPersistenceDirty == 0U))
    {
        return;
    }
    if (PlsrPersistenceDelayMs != 0U)
    {
        return;
    }

    payload.config = PlsrShadowConfig;
    criticalState = PlsrPlatformEnterCritical();
    payload.position = PlsrPosition;
    payload.positionValid = PlsrPositionValid;
    PlsrPlatformExitCritical(criticalState);
    payload.wasBusy = 0U;
    payload.reserved = 0U;
    if (PlsrPlatformSave(&payload) != 0U)
    {
        PlsrPersistenceDirty = 0U;
    }
    else
    {
        PlsrRunStatus = PLSR_STATUS_ERROR;
        PlsrError = PLSR_ERROR_INTERNAL;
    }
}

uint8_t PlsrInit(void)
{
    PLSR_PERSIST_PAYLOAD payload;

    PlsrInitialized = 0U;
    PlsrRunStatus = PLSR_STATUS_UNINITIALIZED;
    if (PlsrPlatformInit() == 0U)
    {
        return 0U;
    }

    if ((PlsrPlatformLoad(&payload) == 0U)
        || (PlsrConfigIsValid(&payload.config, 0U) == 0U)
        || (payload.positionValid > 1U) || (payload.wasBusy > 1U))
    {
        PlsrSetDefaults(&PlsrShadowConfig);
        PlsrPosition = 0L;
        PlsrPositionValid = 1U;
        PlsrPlatformCheckpointConfig(&PlsrShadowConfig);
        PlsrPlatformCheckpointPosition(0L, 1U, 0U);
        PlsrMarkPersistenceDirty(PLSR_CONFIG_SAVE_DELAY_MS);
    }
    else
    {
        PlsrShadowConfig = payload.config;
        PlsrPosition = payload.position;
        PlsrPositionValid = ((payload.positionValid != 0U)
                             && (payload.wasBusy == 0U)) ? 1U : 0U;
        PlsrPersistenceDirty = 0U;
        PlsrPersistenceDelayMs = 0U;
    }

    (void)memset(&PlsrActiveConfig, 0, sizeof(PlsrActiveConfig));
    (void)memset(&PlsrRamp, 0, sizeof(PlsrRamp));
    (void)memset(&PlsrShortProfile, 0, sizeof(PlsrShortProfile));
    (void)memset(&PlsrProfileQueue, 0, sizeof(PlsrProfileQueue));
    (void)memset(&PlsrHandoffPlan, 0, sizeof(PlsrHandoffPlan));
    (void)memset(&PlsrExecutor, 0, sizeof(PlsrExecutor));
    (void)memset(PlsrPreparedHandoffPlans, 0,
                 sizeof(PlsrPreparedHandoffPlans));
    PlsrPreparedHandoffBank = 0U;
    PlsrRemainingPulses = 0UL;
    PlsrPulseActive = 0U;
    PlsrCutRequested = 0U;
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrCountOverflowPending = 0U;
    PlsrPositionCheckpointDirty = 0U;
    PlsrFrequencyUpdatePending = 0U;
    PlsrDeferredFrequencyPending = 0U;
    PlsrFrequencyUpdateSegment = 0U;
    PlsrSeamlessHandoffPending = 0U;
    PlsrTimerErrorPending = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrBoundaryFrequencyHz = 0UL;
    PlsrFrequencyUpdateTargetHz = 0UL;
    PlsrDeferredFrequencyHz = 0UL;
    PlsrSegmentEpoch = 0UL;
    PlsrCurrentSegment = 0U;
    PlsrDirectionDelayActive = 0U;
    PlsrDirectionDelayRemainingMs = 0U;
    PlsrSegmentClockStarted = 0U;
    PlsrExtPreviousLevel = 0U;
    PlsrExtEdgePending = 0U;
    PlsrStopRequested = 0U;
    PlsrStopPulsesRemaining = 0U;
    PlsrAbStopArmed = 0U;
    PlsrLastDirectionValid = 0U;
    PlsrPositionCheckpointElapsedMs = 0U;
    PlsrCommandMailbox.command = 0U;
    PlsrCommandMailbox.state = PLSR_COMMAND_MAILBOX_EMPTY;
    PlsrDiagnosticReset();
#ifdef PLSR_HOST_TEST
    PlsrHostTestEventSequence = 0UL;
    PlsrHostTestLastGateEvent = 0UL;
    PlsrHostTestLastDiagnosticFinishEvent = 0UL;
#endif
#if defined(PLSR_DEBUG_TIMING) && (PLSR_DEBUG_TIMING != 0)
    PlsrProfileProducerItemCount = 0UL;
    PlsrProfileProducerTotalCycles = 0UL;
    PlsrProfileProducerMaxItemCycles = 0UL;
#endif
    PlsrError = PLSR_ERROR_NONE;
    PlsrRunStatus = PLSR_STATUS_IDLE;
    PlsrInitialized = 1U;
    return 1U;
}

static PLSR_MB_RESULT PlsrQueueCommand(uint16_t command)
{
    uint32_t criticalState;
    PLSR_MB_RESULT result = PLSR_MB_OK;

    if (PlsrInitialized == 0U)
    {
        return PLSR_MB_SERVER_FAILURE;
    }

    criticalState = PlsrPlatformEnterCritical();
    /* Capacity one: repeats acknowledge the first command; conflicts wait. */
    if (PlsrCommandMailbox.state != PLSR_COMMAND_MAILBOX_EMPTY)
    {
        result = (PlsrCommandMailbox.command == command)
                     ? PLSR_MB_OK : PLSR_MB_DEVICE_BUSY;
        PlsrPlatformExitCritical(criticalState);
        return result;
    }

    if (command == PLSR_COMMAND_START)
    {
        if ((PlsrIsBusy() != 0U)
            || (PlsrRunStatus == PLSR_STATUS_ERROR))
        {
            result = PLSR_MB_DEVICE_BUSY;
        }
        else if ((PlsrRunStatus != PLSR_STATUS_IDLE)
                 && (PlsrRunStatus != PLSR_STATUS_COMPLETED)
                 && (PlsrRunStatus != PLSR_STATUS_STOPPED))
        {
            result = PLSR_MB_ILLEGAL_VALUE;
        }
        else if ((PlsrConfigIsValid(&PlsrShadowConfig, 1U) == 0U)
                 || ((PlsrShadowConfig.positionMode
                      == PLSR_POSITION_ABSOLUTE)
                     && (PlsrPositionValid == 0U)))
        {
            result = PLSR_MB_ILLEGAL_VALUE;
        }
        else
        {
            PlsrCommandMailbox.startConfig = PlsrShadowConfig;
        }
    }
    else if ((command == PLSR_COMMAND_CLEAR) && (PlsrIsBusy() != 0U))
    {
        result = PLSR_MB_DEVICE_BUSY;
    }

    if (result == PLSR_MB_OK)
    {
        PlsrCommandMailbox.command = command;
        PlsrCommandMailbox.state = PLSR_COMMAND_MAILBOX_PENDING;
    }
    PlsrPlatformExitCritical(criticalState);
    return result;
}

static void PlsrExecuteStart(void)
{
    uint32_t criticalState;
    uint8_t handoffBank;
    uint8_t index;

    PlsrActiveConfig = PlsrCommandMailbox.startConfig;
    for (index = 0U; index < PlsrActiveConfig.segmentCount; index++)
    {
        PlsrActiveConfig.segments[index].frequencyHz =
            PlsrResolvedSegmentFrequency(&PlsrActiveConfig, index);
    }
    handoffBank = PlsrBuildHandoffPlanBank(&PlsrActiveConfig);
    criticalState = PlsrPlatformEnterCritical();
    PlsrPreparedHandoffBank = handoffBank;
    PlsrHandoffPlan.valid = 0U;
    PlsrPlatformExitCritical(criticalState);
    PlsrStopRequested = 0U;
    PlsrTimerErrorPending = 0U;
    PlsrShortProfile.active = 0U;
    PlsrError = PLSR_ERROR_NONE;
    PlsrLastDirectionValid = 0U;
    PlsrCheckpointPosition(1U);
    if (PlsrStartSegment((uint8_t)PlsrActiveConfig.startSegment, 0U, 0UL)
        == 0U)
    {
        PlsrEnterError((PlsrTimerErrorPending != 0U)
                           ? PLSR_ERROR_TIMER
                           : PLSR_ERROR_INVALID_RESOURCE);
    }
}

static uint8_t PlsrExecuteStop(void)
{
    uint32_t criticalState;
    uint32_t stopTargetHz;
    uint32_t appliedHz;
    uint64_t drainPulses;

    if (PlsrIsBusy() == 0U)
    {
        return 0U;
    }
    criticalState = PlsrPlatformEnterCritical();
    if (PlsrStopRequested != 0U)
    {
        PlsrPlatformExitCritical(criticalState);
        return 0U;
    }

    PlsrStopRequested = 1U;
    PlsrStopPulsesRemaining = 0U;
    PlsrShortProfile.active = 0U;
    PlsrProfileQueueInvalidateGeneration();
    PlsrHandoffPlan.valid = 0U;
    PlsrInvalidateHandoffPlans();
    if (PlsrBoundaryPending != 0U)
    {
        PlsrPlatformExitCritical(criticalState);
        return 1U;
    }
    if (PlsrPulseActive == 0U)
    {
        PlsrPlatformExitCritical(criticalState);
        PlsrFinishStopped();
        return 1U;
    }

    stopTargetHz = PlsrEffectiveStopFrequency(
        PlsrActiveConfig.segments[PlsrCurrentSegment - 1U].frequencyHz);
    appliedHz = (PlsrQueuedFrequencyHz != 0UL)
                    ? PlsrQueuedFrequencyHz : PlsrCurrentFrequencyHz;
    if (stopTargetHz > appliedHz)
    {
        stopTargetHz = appliedHz;
    }
    if (PlsrActiveConfig.outputMode == PLSR_OUTPUT_PULSE_DIR)
    {
        drainPulses = PlsrRampPulseEstimate(appliedHz, stopTargetHz,
                                            appliedHz) + 1ULL;
        if (drainPulses > PlsrRemainingPulses)
        {
            drainPulses = PlsrRemainingPulses;
        }
        if (drainPulses == 0ULL)
        {
            drainPulses = 1ULL;
        }
        PlsrRemainingPulses = drainPulses;
        if (PlsrReplanPulseDir(stopTargetHz,
                               (uint32_t)drainPulses) == 0U)
        {
            PlsrPlatformExitCritical(criticalState);
            PlsrEnterError(PLSR_ERROR_TIMER);
            return 1U;
        }
        PlsrRunStatus = PLSR_STATUS_DECELERATING;
        PlsrPlatformExitCritical(criticalState);
        return 1U;
    }
    PlsrRampStart(PlsrCurrentFrequencyHz, stopTargetHz);
    PlsrRunStatus = PLSR_STATUS_DECELERATING;
    if (PlsrRamp.active == 0U)
    {
        if (PlsrApplyFrequency(stopTargetHz, PlsrSegmentEpoch) == 0U)
        {
            PlsrPlatformExitCritical(criticalState);
            PlsrEnterError(PLSR_ERROR_TIMER);
            return 1U;
        }
        (void)PlsrArmStopDrainLocked();
    }
    PlsrPlatformExitCritical(criticalState);
    return 1U;
}

static void PlsrExecuteClear(void)
{
    uint32_t criticalState;

    criticalState = PlsrPlatformEnterCritical();
    PlsrPosition = 0L;
    PlsrPositionValid = 1U;
    PlsrRemainingPulses = 0UL;
    PlsrPlatformExitCritical(criticalState);
    PlsrPlatformCheckpointPosition(0L, 1U, 0U);
    PlsrCountOverflowPending = 0U;
    PlsrPositionCheckpointDirty = 0U;
    PlsrPositionCheckpointElapsedMs = 0U;
    PlsrCurrentSegment = 0U;
    PlsrCurrentFrequencyHz = 0UL;
    PlsrQueuedFrequencyHz = 0UL;
    PlsrCutRequested = 0U;
    PlsrBoundaryPending = 0U;
    PlsrBoundaryWasCut = 0U;
    PlsrDirectionDelayActive = 0U;
    PlsrDirectionDelayRemainingMs = 0U;
    PlsrExtEdgePending = 0U;
    PlsrShortProfile.active = 0U;
    PlsrProfileQueueReset();
    PlsrHandoffPlan.valid = 0U;
    PlsrInvalidateHandoffPlans();
    PlsrDeferredFrequencyPending = 0U;
    PlsrTimerErrorPending = 0U;
    PlsrRamp.active = 0U;
    PlsrExecutor.mode = PLSR_EXEC_IDLE;
    PlsrError = PLSR_ERROR_NONE;
    PlsrRunStatus = PLSR_STATUS_IDLE;
    PlsrMarkPersistenceDirty(PLSR_CONFIG_SAVE_DELAY_MS);
}

static uint8_t PlsrPollCommandMailbox(void)
{
    uint16_t command;
    uint8_t endPoll = 1U;
    uint32_t criticalState;

    criticalState = PlsrPlatformEnterCritical();
    if (PlsrCommandMailbox.state != PLSR_COMMAND_MAILBOX_PENDING)
    {
        PlsrPlatformExitCritical(criticalState);
        return 0U;
    }
    PlsrCommandMailbox.state = PLSR_COMMAND_MAILBOX_EXECUTING;
    command = PlsrCommandMailbox.command;
    PlsrPlatformExitCritical(criticalState);

    switch (command)
    {
        case PLSR_COMMAND_START: PlsrExecuteStart(); break;
        case PLSR_COMMAND_STOP: endPoll = PlsrExecuteStop(); break;
        case PLSR_COMMAND_CLEAR: PlsrExecuteClear(); break;
        default: PlsrEnterError(PLSR_ERROR_INTERNAL); break;
    }

    criticalState = PlsrPlatformEnterCritical();
    PlsrCommandMailbox.command = 0U;
    PlsrCommandMailbox.state = PLSR_COMMAND_MAILBOX_EMPTY;
    PlsrPlatformExitCritical(criticalState);
    return endPoll;
}

static void PlsrEnterErrorIfEpoch(PLSR_ERROR error, uint32_t expectedEpoch)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();

    if (PlsrSegmentEpoch == expectedEpoch)
    {
        PlsrEnterError(error);
    }
    PlsrPlatformExitCritical(criticalState);
}

void PlsrPoll1ms(void)
{
    uint8_t extLevel;
    uint8_t extEdge;
    uint8_t activeSegmentNumber;
    uint8_t applyDynamicFrequency = 0U;
    uint8_t pulseDirReplanFailed = 0U;
    PLSR_SEGMENT_CONFIG *activeSegment;
    uint32_t criticalState;
    uint32_t newTargetHz;
    uint32_t pollEpoch;

    if (PlsrInitialized == 0U)
    {
        return;
    }

    if (PlsrPollCommandMailbox() != 0U)
    {
        return;
    }

    PlsrPollPositionCheckpoint();

    if ((PlsrShortProfile.active != 0U)
        && (PlsrProfileQueueFill(PLSR_PROFILE_QUEUE_CAPACITY) == 0U))
    {
        PlsrEnterError(PLSR_ERROR_TIMER);
        return;
    }

    criticalState = PlsrPlatformEnterCritical();
    pollEpoch = PlsrSegmentEpoch;
    extLevel = PlsrPlatformReadInput((uint8_t)PlsrActiveConfig.extInput);
    extEdge = ((extLevel != 0U) && (PlsrExtPreviousLevel == 0U)) ? 1U : 0U;
    PlsrExtPreviousLevel = extLevel;
    if (PlsrExtEdgePending != 0U)
    {
        extEdge = 1U;
    }
    PlsrPlatformExitCritical(criticalState);

    if (PlsrBoundaryPending != 0U)
    {
        PlsrExtEdgePending = 0U;
        PlsrHandleBoundary(extEdge);
        PlsrPollPersistenceDelay();
        return;
    }

    if (PlsrIsBusy() == 0U)
    {
        PlsrExtEdgePending = 0U;
        PlsrPollPersistenceDelay();
        return;
    }

    if (PlsrSegmentEpoch != pollEpoch)
    {
        return;
    }

    if (PlsrDirectionDelayActive != 0U)
    {
        if (extEdge != 0U)
        {
            PlsrExtEdgePending = 1U;
        }
        if (PlsrDirectionDelayRemainingMs != 0U)
        {
            PlsrDirectionDelayRemainingMs--;
        }
        if (PlsrDirectionDelayRemainingMs == 0U)
        {
            PlsrDirectionDelayActive = 0U;
            if (PlsrBeginSegmentOutput(PlsrEffectiveStartFrequency(
                    PlsrActiveConfig.segments[PlsrCurrentSegment - 1U]
                        .frequencyHz,
                    0U, 1U, 0UL)) == 0U)
            {
                PlsrEnterError(PLSR_ERROR_TIMER);
            }
        }
        return;
    }

    criticalState = PlsrPlatformEnterCritical();
    if (PlsrSegmentEpoch != pollEpoch)
    {
        PlsrPlatformExitCritical(criticalState);
        return;
    }
    PlsrExtEdgePending = 0U;
    if (PlsrSegmentClockStarted != 0U)
    {
        PlsrSegmentElapsedMs++;
    }
    if (PlsrRunStatus == PLSR_STATUS_WAITING)
    {
        PlsrPlatformExitCritical(criticalState);
        PlsrPollWaiting(extEdge);
        return;
    }

    activeSegmentNumber = PlsrCurrentSegment;
    if ((activeSegmentNumber == 0U)
        || (activeSegmentNumber > PlsrActiveConfig.segmentCount))
    {
        PlsrPlatformExitCritical(criticalState);
        PlsrEnterError(PLSR_ERROR_INTERNAL);
        return;
    }
    activeSegment = &PlsrActiveConfig.segments[activeSegmentNumber - 1U];
    if (PlsrSeamlessHandoffPending != 0U)
    {
        PlsrSeamlessHandoffPending = 0U;
        if ((PlsrStopRequested == 0U)
            && (PlsrShortProfile.active == 0U)
            && (PlsrFrequencyUpdatePending == 0U))
        {
            PlsrRamp.active = 0U;
            PlsrRunStatus = PLSR_STATUS_RUNNING;
        }
    }
    newTargetHz = PlsrFrequencyUpdateTargetHz;
    if ((PlsrStopRequested == 0U)
        && (PlsrFrequencyUpdatePending != 0U)
        && (PlsrAbStopArmed == 0U)
        && (PlsrFrequencyUpdateSegment == activeSegmentNumber))
    {
        PlsrFrequencyUpdatePending = 0U;
        activeSegment->frequencyHz = newTargetHz;
        PlsrShortProfile.active = 0U;
        PlsrProfileQueueInvalidateGeneration();
        PlsrBoundaryRampStarted = 0U;
        if (PlsrActiveConfig.outputMode == PLSR_OUTPUT_PULSE_DIR)
        {
            uint64_t remaining = PlsrRemainingPulses;

            if ((remaining == 0ULL) || (remaining > 0xFFFFFFFFULL)
                || (PlsrReplanPulseDir(newTargetHz,
                                       (uint32_t)remaining) == 0U))
            {
                pulseDirReplanFailed = 1U;
            }
        }
        else
        {
            PlsrRampStart(PlsrCurrentFrequencyHz, newTargetHz);
            if (PlsrRamp.active == 0U)
            {
                applyDynamicFrequency = 1U;
            }
        }
    }
    PlsrPlatformExitCritical(criticalState);

    if (pulseDirReplanFailed != 0U)
    {
        PlsrEnterErrorIfEpoch(PLSR_ERROR_TIMER, pollEpoch);
        return;
    }

    if (applyDynamicFrequency != 0U)
    {
        if (PlsrApplyFrequency(newTargetHz, pollEpoch) == 0U)
        {
            PlsrEnterErrorIfEpoch(PLSR_ERROR_TIMER, pollEpoch);
            return;
        }
        criticalState = PlsrPlatformEnterCritical();
        if (PlsrSegmentEpoch == pollEpoch)
        {
            PlsrRunStatus = PLSR_STATUS_RUNNING;
        }
        PlsrPlatformExitCritical(criticalState);
    }

    if ((PlsrActiveConfig.outputMode == PLSR_OUTPUT_AB)
        && (PlsrShortProfile.active == 0U)
        && (PlsrRamp.active != 0U)
        && (PlsrRampAdvance(pollEpoch) == 0U))
    {
        PlsrEnterErrorIfEpoch(PLSR_ERROR_TIMER, pollEpoch);
        return;
    }

    criticalState = PlsrPlatformEnterCritical();
    if (PlsrSegmentEpoch != pollEpoch)
    {
        PlsrPlatformExitCritical(criticalState);
        return;
    }
    if ((PlsrActiveConfig.outputMode == PLSR_OUTPUT_AB)
        && (PlsrStopRequested != 0U) && (PlsrRamp.active == 0U))
    {
        if (PlsrStopPulsesRemaining == 0U)
        {
            if (PlsrArmStopDrainLocked() == 0U)
            {
                PlsrPlatformExitCritical(criticalState);
                PlsrEnterError(PLSR_ERROR_TIMER);
                return;
            }
        }
        else
        {
            (void)PlsrArmFinalAbBoundaryLocked();
        }
        PlsrPlatformExitCritical(criticalState);
        return;
    }
    PlsrPlatformExitCritical(criticalState);

    if ((activeSegment->waitType == PLSR_ACT_TIME)
        && (PlsrSegmentElapsedMs >= activeSegment->actTimeMs))
    {
        PlsrRequestCut(pollEpoch);
        return;
    }
    if (((activeSegment->waitType == PLSR_EXT_SIGNAL)
         || (activeSegment->waitType == PLSR_EXT_OR_COMPLETE))
        && (extEdge != 0U))
    {
        PlsrRequestCut(pollEpoch);
        return;
    }

    if (PlsrActiveConfig.outputMode == PLSR_OUTPUT_AB)
    {
        PlsrMaybePlanBoundaryRamp(pollEpoch);
    }
}

void PlsrPulseTimerIrq(uint8_t pulseOutput)
{
    uint32_t positionBits;
    uint32_t completedFrequencyHz;
    uint64_t remainingPulses;
    PLSR_PLATFORM_QUEUE_RESULT queueResult;

    if ((PlsrPulseActive == 0U)
        || (pulseOutput != (uint8_t)PlsrActiveConfig.pulseOutput))
    {
        return;
    }

    completedFrequencyHz = PlsrCurrentFrequencyHz;
    PlsrDiagnosticCheckActiveFrequency(completedFrequencyHz);
    PlsrCurrentFrequencyHz = PlsrPlatformActiveFrequency(pulseOutput);
    if (PlsrCurrentFrequencyHz == 0UL)
    {
        PlsrCurrentFrequencyHz = PlsrQueuedFrequencyHz;
    }
    if ((PlsrStopRequested != 0U) && (PlsrRamp.active == 0U)
        && (PlsrStopPulsesRemaining != 0U))
    {
        PlsrStopPulsesRemaining--;
        if (PlsrStopPulsesRemaining == 0U)
        {
            PlsrCutRequested = 1U;
        }
    }
    positionBits = (uint32_t)PlsrPosition;
    if (PlsrCountPositive != 0U)
    {
        if (positionBits == (uint32_t)INT32_MAX)
        {
            PlsrPositionValid = 0U;
            PlsrCountOverflowPending = 1U;
        }
        positionBits++;
    }
    else
    {
        if (positionBits == (uint32_t)INT32_MIN)
        {
            PlsrPositionValid = 0U;
            PlsrCountOverflowPending = 1U;
        }
        positionBits--;
    }
    PlsrPosition = (int32_t)positionBits;
    PlsrPositionCheckpointDirty = 1U;

    remainingPulses = PlsrRemainingPulses;
    if (remainingPulses != 0UL)
    {
        remainingPulses--;
        PlsrRemainingPulses = remainingPulses;
    }

    if ((remainingPulses == 0UL) || (PlsrCutRequested != 0U)
        || (PlsrCountOverflowPending != 0U))
    {
        if (remainingPulses == 0UL)
        {
            queueResult = PlsrTryContinuousHandoff();
            if (queueResult != PLSR_PLATFORM_QUEUE_FAILED)
            {
                return;
            }
        }
        PlsrPlatformGateFromIrq(pulseOutput);
#ifdef PLSR_HOST_TEST
        PlsrHostTestEventSequence++;
        PlsrHostTestLastGateEvent = PlsrHostTestEventSequence;
#endif
        PlsrDiagnosticFinishSegment(
            ((remainingPulses == 0UL)
             && (PlsrCutRequested == 0U)
             && (PlsrCountOverflowPending == 0U)) ? 1U : 0U);
        PlsrShortProfile.active = 0U;
        PlsrHandoffPlan.valid = 0U;
        PlsrBoundaryFrequencyHz = completedFrequencyHz;
        PlsrBoundaryWasCut = (PlsrCutRequested != 0U) ? 1U : 0U;
        PlsrCutRequested = 0U;
        PlsrAbStopArmed = 0U;
        PlsrPulseActive = 0U;
        PlsrCurrentFrequencyHz = 0UL;
        PlsrQueuedFrequencyHz = 0UL;
        PlsrBoundaryPending = 1U;
        return;
    }

    if (PlsrShortProfile.active != 0U)
    {
        queueResult = PlsrProfileQueueCommitNext(pulseOutput);
        if (queueResult == PLSR_PLATFORM_QUEUE_STALE)
        {
            return;
        }
        if (queueResult == PLSR_PLATFORM_QUEUE_FAILED)
        {
            PlsrDiagnosticFinishSegment(0U);
            PlsrTimerErrorPending = 1U;
            PlsrShortProfile.active = 0U;
            PlsrHandoffPlan.valid = 0U;
            PlsrBoundaryFrequencyHz = completedFrequencyHz;
            PlsrBoundaryWasCut = 0U;
            PlsrCutRequested = 0U;
            PlsrPlatformGateFromIrq(pulseOutput);
            PlsrAbStopArmed = 0U;
            PlsrPulseActive = 0U;
            PlsrCurrentFrequencyHz = 0UL;
            PlsrQueuedFrequencyHz = 0UL;
            PlsrBoundaryPending = 1U;
            return;
        }
    }

    if ((PlsrShortProfile.active == 0U)
        && (remainingPulses == 1UL))
    {
        if (PlsrPrimeHandoff() == PLSR_PLATFORM_QUEUE_STALE)
        {
            return;
        }
    }
    if ((PlsrShortProfile.active == 0U)
        && (PlsrHandoffPlan.valid == 0U)
        && (PlsrDeferredFrequencyPending != 0U))
    {
        queueResult = PlsrCommitDeferredFrequency(pulseOutput);
        if (queueResult == PLSR_PLATFORM_QUEUE_STALE)
        {
            return;
        }
        if (queueResult == PLSR_PLATFORM_QUEUE_FAILED)
        {
            PlsrDiagnosticFinishSegment(0U);
            PlsrTimerErrorPending = 1U;
            PlsrBoundaryFrequencyHz = completedFrequencyHz;
            PlsrBoundaryWasCut = 0U;
            PlsrCutRequested = 0U;
            PlsrPlatformGateFromIrq(pulseOutput);
            PlsrAbStopArmed = 0U;
            PlsrPulseActive = 0U;
            PlsrCurrentFrequencyHz = 0UL;
            PlsrQueuedFrequencyHz = 0UL;
            PlsrBoundaryPending = 1U;
            return;
        }
    }
    if ((PlsrActiveConfig.outputMode == PLSR_OUTPUT_AB)
        && (PlsrQueueFinalAbBoundaryFromIrq() == 0U))
    {
        return;
    }

}

PLSR_MB_RESULT PlsrModbusReadHolding(uint16_t startAddress,
                                     uint16_t quantity,
                                     uint16_t *values)
{
    PLSR_MB_RESULT classification;
    uint16_t index;
    uint32_t criticalState;
    int32_t position;
    uint32_t frequency;
    uint16_t statusWords[7];
    uint16_t diagnosticWords[26];

    if (values == NULL)
    {
        return PLSR_MB_ILLEGAL_VALUE;
    }
    classification = PlsrClassifyRange(startAddress, quantity);
    if (classification != PLSR_MB_OK)
    {
        return classification;
    }

    criticalState = PlsrPlatformEnterCritical();
    position = PlsrPosition;
    frequency = PlsrCurrentFrequencyHz;
    statusWords[0] = PlsrLowWord((uint32_t)position);
    statusWords[1] = PlsrHighWord((uint32_t)position);
    statusWords[2] = PlsrLowWord(frequency);
    statusWords[3] = PlsrHighWord(frequency);
    statusWords[4] = (uint16_t)PlsrRunStatus;
    statusWords[5] = PlsrCurrentSegment;
    statusWords[6] = (uint16_t)PlsrError;
    diagnosticWords[0] = PlsrDiagnostic.flags;
    diagnosticWords[1] = PlsrDiagnostic.reason;
    diagnosticWords[2] = PlsrDiagnostic.lastSegment;
    diagnosticWords[3] = PlsrDiagnostic.modeDirection;
    diagnosticWords[4] = PlsrLowWord(PlsrDiagnostic.expectedCycles);
    diagnosticWords[5] = PlsrHighWord(PlsrDiagnostic.expectedCycles);
    diagnosticWords[6] = PlsrLowWord(PlsrDiagnostic.observedCycles);
    diagnosticWords[7] = PlsrHighWord(PlsrDiagnostic.observedCycles);
    diagnosticWords[8] = PlsrLowWord((uint32_t)PlsrDiagnostic.countError);
    diagnosticWords[9] = PlsrHighWord((uint32_t)PlsrDiagnostic.countError);
    diagnosticWords[10] = PlsrLowWord(PlsrDiagnostic.requestedHz);
    diagnosticWords[11] = PlsrHighWord(PlsrDiagnostic.requestedHz);
    diagnosticWords[12] = PlsrLowWord(PlsrDiagnostic.expectedTimerHz);
    diagnosticWords[13] = PlsrHighWord(PlsrDiagnostic.expectedTimerHz);
    diagnosticWords[14] = PlsrLowWord(PlsrDiagnostic.activeTimerHz);
    diagnosticWords[15] = PlsrHighWord(PlsrDiagnostic.activeTimerHz);
    diagnosticWords[16] =
        PlsrLowWord((uint32_t)PlsrDiagnostic.requestErrorHz);
    diagnosticWords[17] =
        PlsrHighWord((uint32_t)PlsrDiagnostic.requestErrorHz);
    diagnosticWords[18] = PlsrLowWord(PlsrDiagnostic.curveSampleCount);
    diagnosticWords[19] = PlsrHighWord(PlsrDiagnostic.curveSampleCount);
    diagnosticWords[20] = PlsrLowWord(PlsrDiagnostic.curveMismatchCount);
    diagnosticWords[21] = PlsrHighWord(PlsrDiagnostic.curveMismatchCount);
    diagnosticWords[22] = PlsrLowWord(PlsrDiagnostic.curveMaxAbsErrorHz);
    diagnosticWords[23] = PlsrHighWord(PlsrDiagnostic.curveMaxAbsErrorHz);
    diagnosticWords[24] = PlsrLowWord(PlsrDiagnostic.firstMismatchSample);
    diagnosticWords[25] = PlsrHighWord(PlsrDiagnostic.firstMismatchSample);
    PlsrPlatformExitCritical(criticalState);

    for (index = 0U; index < quantity; index++)
    {
        uint16_t address = (uint16_t)(startAddress + index);

        if ((address >= PLSR_CONFIG_FIRST_ADDRESS)
            && (address <= PLSR_CONFIG_LAST_ADDRESS))
        {
            values[index] = PlsrReadConfigWord(&PlsrShadowConfig, address);
        }
        else if (address == PLSR_OUTPUT_MODE_ADDRESS)
        {
            values[index] = PlsrShadowConfig.outputMode;
        }
        else if ((address >= PLSR_STATUS_FIRST_ADDRESS)
                 && (address <= PLSR_STATUS_LAST_ADDRESS))
        {
            values[index] = statusWords[address - PLSR_STATUS_FIRST_ADDRESS];
        }
        else if ((address >= PLSR_DIAGNOSTIC_FIRST_ADDRESS)
                 && (address <= PLSR_DIAGNOSTIC_LAST_ADDRESS))
        {
            values[index] =
                diagnosticWords[address - PLSR_DIAGNOSTIC_FIRST_ADDRESS];
        }
        else if (address == PLSR_CONTROL_ADDRESS)
        {
            values[index] = 0U;
        }
        else if (address == PLSR_DIAGNOSTIC_CONTROL_ADDRESS)
        {
            values[index] = 0U;
        }
        else
        {
            return PLSR_MB_ILLEGAL_ADDRESS;
        }
    }
    return PLSR_MB_OK;
}

PLSR_MB_RESULT PlsrModbusWriteHolding(uint16_t startAddress,
                                      uint16_t quantity,
                                      const uint16_t *values)
{
    PLSR_MB_RESULT classification;
    PLSR_WORD_RESULT wordResult;
    uint16_t index;
    uint16_t pairedAddress;
    uint32_t requestEnd;
    uint32_t criticalState;
    uint8_t handoffBank = 0U;
    uint8_t updateActiveFrequencies = 0U;
    uint8_t drainedToDifferentSegment = 0U;
    uint8_t segmentBeforeDrain;
    uint32_t drainedSegmentTargetHz = 0UL;
    PLSR_PLATFORM_QUEUE_RESULT queueResult;

    if (values == NULL)
    {
        return PLSR_MB_ILLEGAL_VALUE;
    }
    classification = PlsrClassifyRange(startAddress, quantity);
    if (classification != PLSR_MB_OK)
    {
        return classification;
    }

    if ((startAddress >= PLSR_STATUS_FIRST_ADDRESS)
        && (startAddress <= PLSR_STATUS_LAST_ADDRESS))
    {
        return PLSR_MB_ILLEGAL_ADDRESS;
    }

    if ((startAddress >= PLSR_DIAGNOSTIC_FIRST_ADDRESS)
        && (startAddress <= PLSR_DIAGNOSTIC_LAST_ADDRESS))
    {
        return PLSR_MB_ILLEGAL_ADDRESS;
    }

    if (startAddress == PLSR_DIAGNOSTIC_CONTROL_ADDRESS)
    {
        if (quantity != 1U)
        {
            return PLSR_MB_ILLEGAL_ADDRESS;
        }
        if ((values[0] != 0U) && (values[0] != 1U))
        {
            return PLSR_MB_ILLEGAL_VALUE;
        }
        if ((values[0] != 0U) && (PlsrIsBusy() != 0U))
        {
            return PLSR_MB_DEVICE_BUSY;
        }
        if (values[0] != 0U)
        {
            criticalState = PlsrPlatformEnterCritical();
            PlsrDiagnosticReset();
            PlsrPlatformExitCritical(criticalState);
        }
        return PLSR_MB_OK;
    }

    if (startAddress == PLSR_CONTROL_ADDRESS)
    {
        if (quantity != 1U)
        {
            return PLSR_MB_ILLEGAL_ADDRESS;
        }
        switch (values[0])
        {
            case 0U: return PLSR_MB_OK;
            case PLSR_COMMAND_START:
            case PLSR_COMMAND_STOP:
            case PLSR_COMMAND_CLEAR:
                return PlsrQueueCommand(values[0]);
            default: return PLSR_MB_ILLEGAL_VALUE;
        }
    }

    if (startAddress == PLSR_OUTPUT_MODE_ADDRESS)
    {
        if (quantity != 1U)
        {
            return PLSR_MB_ILLEGAL_ADDRESS;
        }
        if (PlsrIsBusy() != 0U)
        {
            return PLSR_MB_DEVICE_BUSY;
        }
        PlsrCandidateConfig = PlsrShadowConfig;
        PlsrCandidateConfig.outputMode = values[0];
        if (PlsrConfigIsValid(&PlsrCandidateConfig, 0U) == 0U)
        {
            return PLSR_MB_ILLEGAL_VALUE;
        }
        criticalState = PlsrPlatformEnterCritical();
        PlsrShadowConfig = PlsrCandidateConfig;
        PlsrPlatformExitCritical(criticalState);
        PlsrPlatformCheckpointConfig(&PlsrShadowConfig);
        PlsrMarkPersistenceDirty(PLSR_CONFIG_SAVE_DELAY_MS);
        return PLSR_MB_OK;
    }

    if ((startAddress < PLSR_CONFIG_FIRST_ADDRESS)
        || ((uint32_t)startAddress + quantity - 1UL
            > PLSR_CONFIG_LAST_ADDRESS))
    {
        return PLSR_MB_ILLEGAL_ADDRESS;
    }
    if ((PlsrIsBusy() != 0U)
        && (startAddress <= 0x1001U)
        && ((uint32_t)startAddress + quantity - 1UL >= 0x1000UL))
    {
        return PLSR_MB_DEVICE_BUSY;
    }

    requestEnd = (uint32_t)startAddress + quantity;
    for (index = 0U; index < quantity; index++)
    {
        uint16_t address = (uint16_t)(startAddress + index);
        if (PlsrAddressIsDwordHalf(address, &pairedAddress) != 0U)
        {
            if (((uint32_t)pairedAddress < startAddress)
                || ((uint32_t)pairedAddress >= requestEnd))
            {
                return PLSR_MB_ILLEGAL_ADDRESS;
            }
        }
    }

    PlsrCandidateConfig = PlsrShadowConfig;
    for (index = 0U; index < quantity; index++)
    {
        wordResult = PlsrWriteConfigWord(&PlsrCandidateConfig,
                                         (uint16_t)(startAddress + index),
                                         values[index]);
        if (wordResult == PLSR_WORD_ILLEGAL_ADDRESS)
        {
            return PLSR_MB_ILLEGAL_ADDRESS;
        }
        if (wordResult == PLSR_WORD_ILLEGAL_VALUE)
        {
            return PLSR_MB_ILLEGAL_VALUE;
        }
    }

    if (PlsrConfigIsValid(&PlsrCandidateConfig, 0U) == 0U)
    {
        return PLSR_MB_ILLEGAL_VALUE;
    }

    if (PlsrIsBusy() != 0U)
    {
        for (index = 0U; index < PlsrActiveConfig.segmentCount; index++)
        {
            if (PlsrCandidateConfig.segments[index].frequencyHz
                != PlsrShadowConfig.segments[index].frequencyHz)
            {
                updateActiveFrequencies = 1U;
            }
        }
    }
    if (updateActiveFrequencies != 0U)
    {
        handoffBank = PlsrBuildHandoffPlanBank(&PlsrCandidateConfig);
    }

    criticalState = PlsrPlatformEnterCritical();
    segmentBeforeDrain = PlsrCurrentSegment;
    if ((updateActiveFrequencies != 0U) && (PlsrPulseActive != 0U))
    {
        PlsrPlatformDrainPendingPulse(
            (uint8_t)PlsrActiveConfig.pulseOutput);
        drainedToDifferentSegment =
            (PlsrCurrentSegment != segmentBeforeDrain) ? 1U : 0U;
        if ((drainedToDifferentSegment != 0U)
            && (PlsrCurrentSegment != 0U)
            && (PlsrCurrentSegment <= PlsrCandidateConfig.segmentCount))
        {
            drainedSegmentTargetHz = PlsrResolvedSegmentFrequency(
                &PlsrCandidateConfig, PlsrCurrentSegment - 1U);
        }
    }
    PlsrShadowConfig = PlsrCandidateConfig;
    if (updateActiveFrequencies != 0U)
    {
        for (index = 0U; index < PlsrActiveConfig.segmentCount; index++)
        {
            uint8_t frequencyChanged =
                (PlsrActiveConfig.segments[index].frequencyHz
                 != PlsrResolvedSegmentFrequency(&PlsrCandidateConfig, index))
                    ? 1U : 0U;

            PlsrActiveConfig.segments[index].frequencyHz =
                PlsrResolvedSegmentFrequency(&PlsrCandidateConfig, index);
            if ((frequencyChanged != 0U)
                && (index + 1U == PlsrCurrentSegment)
                && (PlsrStopRequested == 0U)
                && (PlsrAbStopArmed == 0U)
                && (PlsrRunStatus != PLSR_STATUS_WAITING))
            {
                PlsrFrequencyUpdateTargetHz =
                    PlsrResolvedSegmentFrequency(&PlsrCandidateConfig,
                                                 index);
                PlsrFrequencyUpdateSegment = (uint8_t)(index + 1U);
                PlsrFrequencyUpdatePending = 1U;
            }
        }
        PlsrPreparedHandoffBank = handoffBank;
        PlsrHandoffPlan.valid = 0U;
        PlsrProfileQueueInvalidateGeneration();
        if ((drainedToDifferentSegment == 0U)
            && (PlsrPulseActive != 0U)
            && (PlsrAbStopArmed == 0U)
            && (PlsrShortProfile.active == 0U)
            && (PlsrRemainingPulses == 1UL))
        {
            (void)PlsrPrimeHandoff();
        }
        if ((drainedToDifferentSegment != 0U)
            && (PlsrPulseActive != 0U)
            && (PlsrCurrentSegment != 0U)
            && (PlsrCurrentSegment <= PlsrActiveConfig.segmentCount)
            && (PlsrStopRequested == 0U)
            && (PlsrAbStopArmed == 0U)
            && (PlsrRunStatus != PLSR_STATUS_WAITING)
            && (PlsrCurrentFrequencyHz != drainedSegmentTargetHz))
        {
            PlsrFrequencyUpdateTargetHz =
                drainedSegmentTargetHz;
            PlsrFrequencyUpdateSegment = PlsrCurrentSegment;
            PlsrFrequencyUpdatePending = 1U;
        }
    }
    PlsrPlatformExitCritical(criticalState);

    if ((updateActiveFrequencies != 0U)
        && (PlsrPulseActive != 0U)
        && (PlsrAbStopArmed == 0U)
        && (PlsrFrequencyUpdatePending == 0U)
        && (PlsrPrepareFutureHandoffQueue() == 0U))
    {
        PlsrTimerErrorPending = 1U;
    }
    if ((drainedToDifferentSegment != 0U)
        && (PlsrAbStopArmed == 0U)
        && (PlsrFrequencyUpdatePending != 0U))
    {
        uint32_t drainEpoch = PlsrSegmentEpoch;
        uint32_t actualDrainFrequencyHz;

        queueResult = PlsrDiagnosticQueueFrequency(
            (uint8_t)PlsrActiveConfig.pulseOutput,
            drainedSegmentTargetHz, &actualDrainFrequencyHz);
        if (queueResult == PLSR_PLATFORM_QUEUE_FAILED)
        {
            PlsrTimerErrorPending = 1U;
        }
        else if (queueResult == PLSR_PLATFORM_QUEUE_APPLIED)
        {
            uint32_t currentEpoch;
            uint8_t updateSegment;
            uint8_t currentSegment;

            criticalState = PlsrPlatformEnterCritical();
            currentEpoch = PlsrSegmentEpoch;
            updateSegment = PlsrFrequencyUpdateSegment;
            currentSegment = PlsrCurrentSegment;
            if ((currentEpoch == drainEpoch)
                && (updateSegment == currentSegment))
            {
                PlsrQueuedFrequencyHz = actualDrainFrequencyHz;
                PlsrFrequencyUpdatePending = 0U;
                PlsrRamp.active = 0U;
                PlsrRunStatus = PLSR_STATUS_RUNNING;
            }
            PlsrPlatformExitCritical(criticalState);
        }
    }
    PlsrPlatformCheckpointConfig(&PlsrShadowConfig);
    PlsrMarkPersistenceDirty(PLSR_CONFIG_SAVE_DELAY_MS);
    return PLSR_MB_OK;
}

#ifdef PLSR_HOST_TEST
void PlsrTestSetPosition(int32_t position, uint8_t positionValid)
{
    uint32_t criticalState = PlsrPlatformEnterCritical();

    PlsrPosition = position;
    PlsrPositionValid = (positionValid != 0U) ? 1U : 0U;
    PlsrRemainingPulses = 0UL;
    PlsrPositionCheckpointDirty = 0U;
    PlsrPlatformExitCritical(criticalState);
    PlsrPlatformCheckpointPosition(position, PlsrPositionValid, 0U);
}

void PlsrTestSetDiagnosticCurveCounts(uint32_t sampleCount,
                                      uint32_t mismatchCount)
{
    PlsrDiagnostic.curveSampleCount = sampleCount;
    PlsrDiagnostic.curveMismatchCount = mismatchCount;
}

void PlsrTestForceProfileQueueEmpty(void)
{
    PlsrProfileQueue.readIndex = PlsrProfileQueue.writeIndex;
    PlsrProfileQueue.generatorComplete = 0U;
    PlsrProfileQueue.active = 1U;
}

uint16_t PlsrTestProfileQueueCount(void)
{
    return PlsrProfileQueueCount();
}

uint32_t PlsrTestProfileQueueGeneration(void)
{
    return PlsrProfileQueue.generation;
}

uint32_t PlsrTestProfileQueueReadIndex(void)
{
    return PlsrProfileQueue.readIndex;
}

uint32_t PlsrTestProfileQueueWriteIndex(void)
{
    return PlsrProfileQueue.writeIndex;
}

uint32_t PlsrTestProfileQueueHeadFrequency(void)
{
    uint32_t readIndex = PlsrProfileQueue.readIndex;

    if (readIndex == PlsrProfileQueue.writeIndex)
    {
        return 0UL;
    }
    return PlsrProfileQueue
        .entries[readIndex & PLSR_PROFILE_QUEUE_MASK].requestedFrequencyHz;
}

uint16_t PlsrTestProfileProducerNextPeriod(void)
{
    return PlsrProfileQueue.producerProfile.nextPeriod;
}

uint16_t PlsrTestActiveProfileNextPeriod(void)
{
    return PlsrShortProfile.nextPeriod;
}

uint32_t PlsrTestLastGateEvent(void)
{
    return PlsrHostTestLastGateEvent;
}

uint32_t PlsrTestLastDiagnosticFinishEvent(void)
{
    return PlsrHostTestLastDiagnosticFinishEvent;
}
#endif