Modbus-rtu/PLSR/Src/plsr_platform_f407.c

#include "plsr_platform.h"
#include "plsr.h"

static uint8_t PlsrFlashNeedsStartupRecovery(
    uint8_t haveValidRecord,
    uint8_t sectorAHasProgrammedSlot,
    uint32_t sectorAFirstErasedAddress,
    uint8_t sectorBHasProgrammedSlot,
    uint32_t sectorBFirstErasedAddress)
{
    return ((haveValidRecord == 0U)
            && (sectorAHasProgrammedSlot != 0U)
            && (sectorBHasProgrammedSlot != 0U)
            && (sectorAFirstErasedAddress == 0UL)
            && (sectorBFirstErasedAddress == 0UL)) ? 1U : 0U;
}

#ifdef PLSR_HOST_TEST

#include <string.h>

static uint8_t PlsrHostPulseActive[4];
static uint32_t PlsrHostFrequency[4];
static uint32_t PlsrHostQueuedFrequency[4];
static PLSR_PLATFORM_TIMER_SETTING PlsrHostActiveSetting[4];
static PLSR_PLATFORM_TIMER_SETTING PlsrHostQueuedSetting[4];
static uint8_t PlsrHostUpdatePending[4];
static uint8_t PlsrHostOutputMode[4];
static uint8_t PlsrHostDirectionPositive[4];
static uint8_t PlsrHostAbQuarter[4];
static uint8_t PlsrHostAbPhase[4];
static uint32_t PlsrHostAbTransitions[4];
static uint8_t PlsrHostAbStopPending[4];
static uint8_t PlsrHostAbFastGated[4];
static uint32_t PlsrHostAbFastGateCount;
static uint32_t PlsrHostAbCleanupCount;
static uint64_t PlsrHostObservedPulses[4];
static uint8_t PlsrHostInputs[2];
static uint8_t PlsrHostSelectedPulse;
static uint8_t PlsrHostDirectionLevel;
static uint8_t PlsrHostDirectionPinLevel[4];
static uint32_t PlsrHostDirectionWriteCount[4];
static uint32_t PlsrHostDirectionTransitionCount[4];
static uint8_t PlsrHostEmitPulseOnCriticalEntry;
static uint8_t PlsrHostEmitPulseOnCriticalExit;
static uint8_t PlsrHostLatchPulseOnCriticalEntry;
static uint8_t PlsrHostCriticalEntriesToSkip;
static uint8_t PlsrHostLatchAbFinalQuarterOnStopArm;
static uint8_t PlsrHostCompleteAbCycleOnQueueCommit;
static uint32_t PlsrHostCriticalDepth;
static uint8_t PlsrHostFailNextStart;
static uint8_t PlsrHostStaleNextFrequencyAtUpdate;
static uint8_t PlsrHostFailNextFrequencyAtUpdate;
static uint8_t PlsrHostFailNextStopRequest;
static uint8_t PlsrHostFinalArmJobPending;
static uint8_t PlsrHostFinalArmJobOwner;
static uint8_t PlsrHostDeferFinalArmJob;
static int32_t PlsrHostCountOffset;
static int32_t PlsrHostFrequencyOffsetHz;
static uint8_t PlsrHostCurveMismatchPending;
static uint16_t PlsrHostDiagnosticFault;
static PLSR_PERSIST_PAYLOAD PlsrHostPersistentPayload;
static uint8_t PlsrHostPersistentValid;
static uint32_t PlsrHostSaveCount;
static uint8_t PlsrHostFiniteEnabled;
static uint8_t PlsrHostFiniteActive[4];
static uint8_t PlsrHostFiniteComplete[4];
static uint8_t PlsrHostFiniteFrequencyPending[4];
static uint8_t PlsrHostCountedStreamActive[4];
static uint32_t PlsrHostFiniteTarget[4];
static uint32_t PlsrHostFiniteEmitted[4];
static PLSR_PLATFORM_FINITE_STEP *PlsrHostFiniteSteps[4];
static uint16_t PlsrHostFiniteStepCount[4];
static uint16_t PlsrHostFiniteStepIndex[4];
static uint16_t PlsrHostFiniteBoundaryReadIndex[4];
static uint16_t PlsrHostFiniteCompletedStepCount[4];

static void PlsrHostServiceFinalArmJob(void);

static uint32_t PlsrHostOffsetFrequency(uint32_t frequencyHz)
{
    int64_t adjusted = (int64_t)frequencyHz
                       + (int64_t)PlsrHostFrequencyOffsetHz;

    if (adjusted < 1)
    {
        adjusted = 1;
    }
    if (adjusted > (int64_t)PLSR_FREQUENCY_MAX_HZ)
    {
        adjusted = (int64_t)PLSR_FREQUENCY_MAX_HZ;
    }
    return (uint32_t)adjusted;
}

static void PlsrHostLatchPulse(uint8_t pulseOutput)
{
    if ((pulseOutput <= 3U)
        && (PlsrHostPulseActive[pulseOutput] != 0U))
    {
        if (PlsrHostCurveMismatchPending != 0U)
        {
            PlsrHostCurveMismatchPending = 0U;
            PlsrHostDiagnosticFault = 3U;
        }
        else if ((PlsrHostOutputMode[pulseOutput] != PLSR_OUTPUT_AB)
                 || (PlsrHostAbStopPending[pulseOutput] == 0U))
        {
            PlsrHostFrequency[pulseOutput] =
                PlsrHostQueuedFrequency[pulseOutput];
            PlsrHostActiveSetting[pulseOutput] =
                PlsrHostQueuedSetting[pulseOutput];
        }
        PlsrHostObservedPulses[pulseOutput]++;
        PlsrHostUpdatePending[pulseOutput] = 1U;
    }
}

static void PlsrHostServicePendingPulse(uint8_t pulseOutput)
{
    if ((pulseOutput <= 3U)
        && (PlsrHostUpdatePending[pulseOutput] != 0U))
    {
        PlsrHostUpdatePending[pulseOutput] = 0U;
        if ((PlsrHostOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
            && (PlsrHostAbStopPending[pulseOutput] != 0U)
            && (PlsrHostAbFastGated[pulseOutput] == 0U))
        {
            PlsrHostAbFastGated[pulseOutput] = 1U;
            PlsrHostPulseActive[pulseOutput] = 0U;
            PlsrHostAbFastGateCount++;
        }
        PlsrPulseTimerIrq(pulseOutput);
    }
    if (PlsrHostDeferFinalArmJob == 0U)
    {
        PlsrHostServiceFinalArmJob();
    }
}

static void PlsrHostServiceFinalArmJob(void)
{
    uint8_t owner;

    if (PlsrHostFinalArmJobPending == 0U)
    {
        return;
    }
    owner = PlsrHostFinalArmJobOwner;
    PlsrHostFinalArmJobPending = 0U;
    PlsrHostFinalArmJobOwner = 0xFFU;
    PlsrFinalArmJobIrq(owner);
}

static uint8_t PlsrHostAdvanceAbQuarter(uint8_t pulseOutput)
{
    static const uint8_t positivePhase[4] = {0U, 2U, 3U, 1U};
    static const uint8_t negativePhase[4] = {0U, 1U, 3U, 2U};

    if ((pulseOutput > 3U)
        || (PlsrHostPulseActive[pulseOutput] == 0U)
        || (PlsrHostOutputMode[pulseOutput] != PLSR_OUTPUT_AB))
    {
        return 0U;
    }
    PlsrHostAbQuarter[pulseOutput] =
        (uint8_t)((PlsrHostAbQuarter[pulseOutput] + 1U) & 3U);
    PlsrHostAbPhase[pulseOutput] =
        (PlsrHostDirectionPositive[pulseOutput] != 0U)
            ? positivePhase[PlsrHostAbQuarter[pulseOutput]]
            : negativePhase[PlsrHostAbQuarter[pulseOutput]];
    PlsrHostAbTransitions[pulseOutput]++;
    if (PlsrHostAbQuarter[pulseOutput] != 0U)
    {
        return 0U;
    }
    PlsrHostLatchPulse(pulseOutput);
    return 1U;
}

uint8_t PlsrPlatformInit(void)
{
    uint8_t index;

    (void)memset(PlsrHostPulseActive, 0, sizeof(PlsrHostPulseActive));
    (void)memset(PlsrHostFrequency, 0, sizeof(PlsrHostFrequency));
    (void)memset(PlsrHostQueuedFrequency, 0,
                 sizeof(PlsrHostQueuedFrequency));
    (void)memset(PlsrHostActiveSetting, 0,
                 sizeof(PlsrHostActiveSetting));
    (void)memset(PlsrHostQueuedSetting, 0,
                 sizeof(PlsrHostQueuedSetting));
    (void)memset(PlsrHostUpdatePending, 0,
                 sizeof(PlsrHostUpdatePending));
    (void)memset(PlsrHostOutputMode, 0, sizeof(PlsrHostOutputMode));
    (void)memset(PlsrHostDirectionPositive, 0,
                 sizeof(PlsrHostDirectionPositive));
    (void)memset(PlsrHostAbQuarter, 0, sizeof(PlsrHostAbQuarter));
    (void)memset(PlsrHostAbPhase, 0, sizeof(PlsrHostAbPhase));
    (void)memset(PlsrHostAbTransitions, 0,
                 sizeof(PlsrHostAbTransitions));
    (void)memset(PlsrHostAbStopPending, 0,
                 sizeof(PlsrHostAbStopPending));
    (void)memset(PlsrHostAbFastGated, 0,
                 sizeof(PlsrHostAbFastGated));
    PlsrHostAbFastGateCount = 0UL;
    PlsrHostAbCleanupCount = 0UL;
    (void)memset(PlsrHostObservedPulses, 0,
                 sizeof(PlsrHostObservedPulses));
    PlsrHostSelectedPulse = 0U;
    PlsrHostDirectionLevel = 0U;
    for (index = 0U; index < 4U; index++)
    {
        PlsrHostDirectionPinLevel[index] = 1U;
        PlsrHostDirectionWriteCount[index] = 0UL;
        PlsrHostDirectionTransitionCount[index] = 0UL;
    }
    PlsrHostEmitPulseOnCriticalEntry = 0U;
    PlsrHostEmitPulseOnCriticalExit = 0U;
    PlsrHostLatchPulseOnCriticalEntry = 0U;
    PlsrHostCriticalEntriesToSkip = 0U;
    PlsrHostLatchAbFinalQuarterOnStopArm = 0U;
    PlsrHostCompleteAbCycleOnQueueCommit = 0U;
    PlsrHostCriticalDepth = 0UL;
    PlsrHostFailNextStart = 0U;
    PlsrHostStaleNextFrequencyAtUpdate = 0U;
    PlsrHostFailNextFrequencyAtUpdate = 0U;
    PlsrHostFailNextStopRequest = 0U;
    PlsrHostFinalArmJobPending = 0U;
    PlsrHostFinalArmJobOwner = 0xFFU;
    PlsrHostDeferFinalArmJob = 0U;
    PlsrHostCountOffset = 0L;
    PlsrHostFrequencyOffsetHz = 0L;
    PlsrHostCurveMismatchPending = 0U;
    PlsrHostDiagnosticFault = 0U;
    PlsrHostFiniteEnabled = 0U;
    (void)memset(PlsrHostFiniteActive, 0, sizeof(PlsrHostFiniteActive));
    (void)memset(PlsrHostFiniteComplete, 0,
                 sizeof(PlsrHostFiniteComplete));
    (void)memset(PlsrHostFiniteFrequencyPending, 0,
                 sizeof(PlsrHostFiniteFrequencyPending));
    (void)memset(PlsrHostFiniteTarget, 0, sizeof(PlsrHostFiniteTarget));
    (void)memset(PlsrHostFiniteEmitted, 0, sizeof(PlsrHostFiniteEmitted));
    (void)memset(PlsrHostFiniteSteps, 0, sizeof(PlsrHostFiniteSteps));
    (void)memset(PlsrHostFiniteStepCount, 0,
                 sizeof(PlsrHostFiniteStepCount));
    (void)memset(PlsrHostFiniteStepIndex, 0,
                 sizeof(PlsrHostFiniteStepIndex));
    (void)memset(PlsrHostFiniteBoundaryReadIndex, 0,
                 sizeof(PlsrHostFiniteBoundaryReadIndex));
    (void)memset(PlsrHostFiniteCompletedStepCount, 0,
                 sizeof(PlsrHostFiniteCompletedStepCount));
    return 1U;
}

uint8_t PlsrPlatformPrepare(uint8_t pulseOutput,
                            uint8_t directionOutput,
                            uint8_t directionLevel,
                            uint8_t outputMode,
                            uint8_t directionPositive)
{
    uint8_t index;
    uint8_t pinLevel;

    if (PlsrHostFailNextStart != 0U)
    {
        PlsrHostFailNextStart = 0U;
        return 0U;
    }
    if ((pulseOutput > 3U) || (directionOutput > 3U)
        || (outputMode > PLSR_OUTPUT_AB)
        || ((outputMode == PLSR_OUTPUT_AB)
            && ((pulseOutput & 1U) != 0U))
        || (PlsrHostAbStopPending[0] != 0U)
        || (PlsrHostAbStopPending[2] != 0U))
    {
        return 0U;
    }
    for (index = 0U; index < 4U; index++)
    {
        PlsrHostPulseActive[index] = 0U;
        PlsrHostFrequency[index] = 0UL;
        PlsrHostQueuedFrequency[index] = 0UL;
        PlsrHostUpdatePending[index] = 0U;
        pinLevel = ((outputMode == PLSR_OUTPUT_PULSE_DIR)
                    && (index == directionOutput)
                    && (directionLevel != 0U)) ? 0U : 1U;
        PlsrHostDirectionWriteCount[index]++;
        if (PlsrHostDirectionPinLevel[index] != pinLevel)
        {
            PlsrHostDirectionTransitionCount[index]++;
        }
        PlsrHostDirectionPinLevel[index] = pinLevel;
    }
    PlsrHostSelectedPulse = pulseOutput;
    PlsrHostDirectionLevel = (directionLevel != 0U) ? 1U : 0U;
    PlsrHostOutputMode[pulseOutput] = outputMode;
    PlsrHostDirectionPositive[pulseOutput] =
        (directionPositive != 0U) ? 1U : 0U;
    PlsrHostAbQuarter[pulseOutput] = 0U;
    PlsrHostAbPhase[pulseOutput] = 0U;
    PlsrHostAbFastGated[pulseOutput] = 0U;
    return 1U;
}

uint8_t PlsrPlatformStartPulse(uint8_t pulseOutput,
                               uint32_t firstFrequencyHz,
                               uint32_t queuedFrequencyHz,
                               uint32_t *actualFirstFrequencyHz,
                               uint32_t *actualQueuedFrequencyHz)
{
    PLSR_PLATFORM_TIMER_SETTING firstSetting;
    PLSR_PLATFORM_TIMER_SETTING queuedSetting;

    if ((pulseOutput > 3U)
        || (PlsrPlatformBuildTimerSetting(
                pulseOutput, PlsrHostOutputMode[pulseOutput],
                firstFrequencyHz, &firstSetting) == 0U)
        || (PlsrPlatformBuildTimerSetting(
                pulseOutput, PlsrHostOutputMode[pulseOutput],
                queuedFrequencyHz, &queuedSetting) == 0U))
    {
        return 0U;
    }
    return PlsrPlatformStartPrepared(pulseOutput, &firstSetting,
                                     &queuedSetting,
                                     actualFirstFrequencyHz,
                                     actualQueuedFrequencyHz);
}

uint8_t PlsrPlatformBuildTimerSetting(
    uint8_t pulseOutput,
    uint8_t outputMode,
    uint32_t requestedFrequencyHz,
    PLSR_PLATFORM_TIMER_SETTING *setting)
{
    if ((pulseOutput > 3U) || (outputMode > PLSR_OUTPUT_AB)
        || ((outputMode == PLSR_OUTPUT_AB)
            && ((pulseOutput & 1U) != 0U))
        || (requestedFrequencyHz == 0UL)
        || (requestedFrequencyHz > PLSR_FREQUENCY_MAX_HZ)
        || (setting == NULL))
    {
        return 0U;
    }
    setting->actualFrequencyHz = requestedFrequencyHz;
    setting->prescaler = (outputMode == PLSR_OUTPUT_AB) ? 1U : 0U;
    setting->pairPrescaler = 0U;
    setting->period = (outputMode == PLSR_OUTPUT_AB) ? 3U : 1U;
    setting->compare = (outputMode == PLSR_OUTPUT_AB) ? 2U : 1U;
    return 1U;
}

uint8_t PlsrPlatformStartPrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *firstSetting,
    const PLSR_PLATFORM_TIMER_SETTING *queuedSetting,
    uint32_t *actualFirstFrequencyHz,
    uint32_t *actualQueuedFrequencyHz)
{
    if ((pulseOutput > 3U) || (firstSetting == NULL)
        || (queuedSetting == NULL) || (actualFirstFrequencyHz == NULL)
        || (actualQueuedFrequencyHz == NULL)
        || (firstSetting->actualFrequencyHz == 0UL)
        || (firstSetting->actualFrequencyHz > PLSR_FREQUENCY_MAX_HZ)
        || (queuedSetting->actualFrequencyHz == 0UL)
        || (queuedSetting->actualFrequencyHz > PLSR_FREQUENCY_MAX_HZ)
        || (PlsrHostAbStopPending[pulseOutput] != 0U)
        || (PlsrHostAbFastGated[pulseOutput] != 0U))
    {
        return 0U;
    }
    PlsrHostPulseActive[pulseOutput] = 1U;
    PlsrHostFrequency[pulseOutput] = firstSetting->actualFrequencyHz;
    PlsrHostQueuedFrequency[pulseOutput] = queuedSetting->actualFrequencyHz;
    PlsrHostActiveSetting[pulseOutput] = *firstSetting;
    PlsrHostQueuedSetting[pulseOutput] = *queuedSetting;
    PlsrHostUpdatePending[pulseOutput] = 0U;
    PlsrHostSelectedPulse = pulseOutput;
    *actualFirstFrequencyHz = firstSetting->actualFrequencyHz;
    *actualQueuedFrequencyHz = queuedSetting->actualFrequencyHz;
    return 1U;
}

uint8_t PlsrPlatformSupportsFinitePulseTrain(void)
{
    return PlsrHostFiniteEnabled;
}

uint8_t PlsrPlatformStartFinitePrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t pulseCount,
    uint32_t *actualFrequencyHz)
{
    if ((PlsrHostFiniteEnabled == 0U) || (pulseOutput > 3U)
        || (setting == NULL) || (pulseCount == 0UL)
        || (actualFrequencyHz == NULL)
        || (PlsrHostOutputMode[pulseOutput] != PLSR_OUTPUT_PULSE_DIR))
    {
        return 0U;
    }
    PlsrHostPulseActive[pulseOutput] = 1U;
    PlsrHostFiniteActive[pulseOutput] = 1U;
    PlsrHostFiniteComplete[pulseOutput] = 0U;
    PlsrHostFiniteFrequencyPending[pulseOutput] = 0U;
    PlsrHostCountedStreamActive[pulseOutput] = 0U;
    PlsrHostFiniteTarget[pulseOutput] = pulseCount;
    PlsrHostFiniteEmitted[pulseOutput] = 0UL;
    PlsrHostFiniteStepCount[pulseOutput] = 0U;
    PlsrHostFiniteStepIndex[pulseOutput] = 0U;
    PlsrHostFiniteBoundaryReadIndex[pulseOutput] = 0U;
    PlsrHostFiniteCompletedStepCount[pulseOutput] = 0U;
    PlsrHostFrequency[pulseOutput] = setting->actualFrequencyHz;
    PlsrHostQueuedFrequency[pulseOutput] = setting->actualFrequencyHz;
    PlsrHostActiveSetting[pulseOutput] = *setting;
    PlsrHostQueuedSetting[pulseOutput] = *setting;
    PlsrHostSelectedPulse = pulseOutput;
    *actualFrequencyHz = setting->actualFrequencyHz;
    return 1U;
}

uint8_t PlsrPlatformStartCountedStreamPrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t pulseCount,
    uint32_t *actualFrequencyHz)
{
    if (PlsrPlatformStartFinitePrepared(pulseOutput, setting, pulseCount,
                                        actualFrequencyHz) == 0U)
    {
        return 0U;
    }
    PlsrHostCountedStreamActive[pulseOutput] = 1U;
    return 1U;
}

uint8_t PlsrPlatformStartFiniteSequencePrepared(
    uint8_t pulseOutput,
    PLSR_PLATFORM_FINITE_STEP *steps,
    uint16_t stepCount,
    uint32_t *actualFrequencyHz)
{
    if ((steps == NULL) || (stepCount == 0U)
        || (stepCount > PLSR_PLATFORM_FINITE_STEP_MAX)
        || (PlsrPlatformStartFinitePrepared(
                pulseOutput, &steps[0].setting, steps[0].pulseCount,
                actualFrequencyHz) == 0U))
    {
        return 0U;
    }
    PlsrHostFiniteSteps[pulseOutput] = steps;
    PlsrHostFiniteStepCount[pulseOutput] = stepCount;
    PlsrHostFiniteStepIndex[pulseOutput] = 0U;
    PlsrHostFiniteBoundaryReadIndex[pulseOutput] = 0U;
    PlsrHostFiniteCompletedStepCount[pulseOutput] = 0U;
    return 1U;
}


PLSR_PLATFORM_QUEUE_RESULT PlsrPlatformUpdateFinitePrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t *actualFrequencyHz)
{
    if (PlsrHostFailNextFrequencyAtUpdate != 0U)
    {
        PlsrHostFailNextFrequencyAtUpdate = 0U;
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if ((pulseOutput > 3U) || (setting == NULL)
        || (actualFrequencyHz == NULL)
        || (PlsrHostFiniteActive[pulseOutput] == 0U))
    {
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    if (PlsrHostStaleNextFrequencyAtUpdate != 0U)
    {
        PlsrHostStaleNextFrequencyAtUpdate = 0U;
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    if (PlsrHostFiniteFrequencyPending[pulseOutput] != 0U)
    {
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    PlsrHostQueuedSetting[pulseOutput] = *setting;
    PlsrHostQueuedFrequency[pulseOutput] = setting->actualFrequencyHz;
    PlsrHostFiniteFrequencyPending[pulseOutput] = 1U;
    *actualFrequencyHz = setting->actualFrequencyHz;
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

uint8_t PlsrPlatformRetargetFiniteStop(uint8_t pulseOutput,
                                       uint32_t drainPulses)
{
    uint32_t completed;

    if ((pulseOutput > 3U) || (drainPulses == 0UL)
        || (PlsrHostFiniteActive[pulseOutput] == 0U))
    {
        return 0U;
    }
    completed = PlsrHostFiniteEmitted[pulseOutput];
    if (PlsrHostFiniteStepCount[pulseOutput] != 0U)
    {
        completed += PlsrHostFiniteSteps[pulseOutput][
            PlsrHostFiniteStepIndex[pulseOutput]].segmentPulseOffset;
    }
    PlsrHostFiniteTarget[pulseOutput] = completed + drainPulses;
    PlsrHostFiniteEmitted[pulseOutput] = completed;
    PlsrHostFiniteStepCount[pulseOutput] = 0U;
    PlsrHostFiniteStepIndex[pulseOutput] = 0U;
    PlsrHostFiniteBoundaryReadIndex[pulseOutput] = 0U;
    PlsrHostFiniteCompletedStepCount[pulseOutput] = 0U;
    return 1U;
}

uint8_t PlsrPlatformFiniteRetargetReady(uint8_t pulseOutput,
                                        uint32_t *activeFrequencyHz)
{
    if ((pulseOutput > 3U) || (activeFrequencyHz == NULL)
        || (PlsrHostFiniteActive[pulseOutput] == 0U))
    {
        return 0U;
    }
    *activeFrequencyHz = PlsrHostFrequency[pulseOutput];
    return (PlsrHostFiniteStepCount[pulseOutput] == 0U) ? 1U : 0U;
}

uint8_t PlsrPlatformFinitePipelineSnapshot(uint8_t pulseOutput,
                                           uint32_t *committedPulses,
                                           uint32_t *tailFrequencyHz,
                                           uint8_t *startsNextSegment)
{
    uint32_t remaining;

    if ((pulseOutput > 3U) || (committedPulses == NULL)
        || (tailFrequencyHz == NULL) || (startsNextSegment == NULL)
        || (PlsrHostFiniteActive[pulseOutput] == 0U))
    {
        return 0U;
    }
    remaining = PlsrHostFiniteTarget[pulseOutput]
                - PlsrHostFiniteEmitted[pulseOutput];
    *committedPulses = remaining;
    *tailFrequencyHz = PlsrHostQueuedFrequency[pulseOutput];
    *startsNextSegment = 0U;
    return 1U;
}

uint8_t PlsrPlatformFiniteProgress(uint8_t pulseOutput,
                                   uint32_t *completedPulses)
{
    if ((pulseOutput > 3U) || (completedPulses == NULL)
        || ((PlsrHostFiniteActive[pulseOutput] == 0U)
            && (PlsrHostFiniteComplete[pulseOutput] == 0U)))
    {
        return 0U;
    }
    if (PlsrHostFiniteStepCount[pulseOutput] != 0U)
    {
        const PLSR_PLATFORM_FINITE_STEP *step =
            &PlsrHostFiniteSteps[pulseOutput][
                PlsrHostFiniteStepIndex[pulseOutput]];

        *completedPulses = step->segmentPulseOffset
                           + PlsrHostFiniteEmitted[pulseOutput];
    }
    else
    {
        *completedPulses = PlsrHostFiniteEmitted[pulseOutput];
    }
    return 1U;
}

uint8_t PlsrPlatformTakeFiniteCompletion(uint8_t pulseOutput,
                                         uint32_t *completedPulses)
{
    if ((pulseOutput > 3U) || (completedPulses == NULL)
        || (PlsrHostFiniteComplete[pulseOutput] == 0U))
    {
        return 0U;
    }
    PlsrHostFiniteComplete[pulseOutput] = 0U;
    if (PlsrHostFiniteStepCount[pulseOutput] != 0U)
    {
        const PLSR_PLATFORM_FINITE_STEP *step =
            &PlsrHostFiniteSteps[pulseOutput][
                PlsrHostFiniteStepCount[pulseOutput] - 1U];

        *completedPulses = step->segmentPulseOffset + step->pulseCount;
    }
    else
    {
        *completedPulses = PlsrHostFiniteTarget[pulseOutput];
    }
    return 1U;
}

uint8_t PlsrPlatformTakeFiniteBoundary(uint8_t pulseOutput,
                                       uint8_t *segmentNumber,
                                       uint32_t *completedPulses,
                                       uint8_t *sequenceContinues,
                                       uint32_t *activeFrequencyHz)
{
    if ((pulseOutput > 3U) || (segmentNumber == NULL)
        || (completedPulses == NULL) || (sequenceContinues == NULL)
        || (activeFrequencyHz == NULL))
    {
        return 0U;
    }
    while (PlsrHostFiniteBoundaryReadIndex[pulseOutput]
           < PlsrHostFiniteCompletedStepCount[pulseOutput])
    {
        uint16_t index = PlsrHostFiniteBoundaryReadIndex[pulseOutput]++;
        const PLSR_PLATFORM_FINITE_STEP *step =
            &PlsrHostFiniteSteps[pulseOutput][index];

        if (step->completesSegment != 0U)
        {
            *segmentNumber = step->segmentNumber;
            *completedPulses = step->segmentPulseOffset + step->pulseCount;
            *sequenceContinues =
                (index + 1U < PlsrHostFiniteStepCount[pulseOutput]) ? 1U : 0U;
            *activeFrequencyHz = (*sequenceContinues != 0U)
                ? PlsrHostFiniteSteps[pulseOutput][index + 1U]
                      .setting.actualFrequencyHz
                : step->setting.actualFrequencyHz;
            return 1U;
        }
    }
    return 0U;
}

PLSR_PLATFORM_QUEUE_RESULT PlsrPlatformLoadPreparedFromIrq(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t *actualFrequencyHz)
{
    if (PlsrHostFailNextFrequencyAtUpdate != 0U)
    {
        PlsrHostFailNextFrequencyAtUpdate = 0U;
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if ((pulseOutput > 3U) || (setting == NULL)
        || (actualFrequencyHz == NULL)
        || (setting->actualFrequencyHz == 0UL)
        || (setting->actualFrequencyHz > PLSR_FREQUENCY_MAX_HZ))
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if (PlsrHostStaleNextFrequencyAtUpdate != 0U)
    {
        PlsrHostStaleNextFrequencyAtUpdate = 0U;
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    if ((PlsrHostCompleteAbCycleOnQueueCommit != 0U)
        && (PlsrHostOutputMode[pulseOutput] == PLSR_OUTPUT_AB))
    {
        PlsrHostCompleteAbCycleOnQueueCommit = 0U;
        PlsrTestEmitAbQuarters(4UL);
    }
    if ((PlsrHostPulseActive[pulseOutput] == 0U)
        || (PlsrHostAbStopPending[pulseOutput] != 0U)
        || (PlsrHostAbFastGated[pulseOutput] != 0U))
    {
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    PlsrHostQueuedSetting[pulseOutput] = *setting;
    PlsrHostQueuedFrequency[pulseOutput] = setting->actualFrequencyHz;
    *actualFrequencyHz = setting->actualFrequencyHz;
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

void PlsrPlatformGateFromIrq(uint8_t pulseOutput)
{
    if ((pulseOutput <= 3U)
        && (PlsrHostOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        && (PlsrHostAbFastGated[pulseOutput] != 0U))
    {
        return;
    }
    PlsrPlatformStopPulse(pulseOutput);
}

PLSR_PLATFORM_QUEUE_RESULT PlsrPlatformQueueFrequency(
    uint8_t pulseOutput,
    uint32_t frequencyHz,
    uint32_t *actualFrequencyHz)
{
    uint32_t criticalState;
    PLSR_PLATFORM_TIMER_SETTING setting;

    if (PlsrHostFailNextFrequencyAtUpdate != 0U)
    {
        PlsrHostFailNextFrequencyAtUpdate = 0U;
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if ((pulseOutput > 3U)
        || (PlsrPlatformBuildTimerSetting(
                pulseOutput, PlsrHostOutputMode[pulseOutput], frequencyHz,
                &setting) == 0U)
        || (actualFrequencyHz == NULL)
        || (PlsrHostPulseActive[pulseOutput] == 0U)
        || (PlsrHostAbStopPending[pulseOutput] != 0U)
        || (PlsrHostAbFastGated[pulseOutput] != 0U))
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if (PlsrHostStaleNextFrequencyAtUpdate != 0U)
    {
        PlsrHostStaleNextFrequencyAtUpdate = 0U;
        return PLSR_PLATFORM_QUEUE_STALE;
    }

    if ((PlsrHostCompleteAbCycleOnQueueCommit != 0U)
        && (PlsrHostOutputMode[pulseOutput] == PLSR_OUTPUT_AB))
    {
        PlsrHostCompleteAbCycleOnQueueCommit = 0U;
        PlsrTestEmitAbQuarters(4UL);
    }

    criticalState = PlsrPlatformEnterCritical();
    if ((PlsrHostPulseActive[pulseOutput] == 0U)
        || (PlsrHostAbStopPending[pulseOutput] != 0U)
        || (PlsrHostAbFastGated[pulseOutput] != 0U))
    {
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    PlsrHostQueuedFrequency[pulseOutput] = setting.actualFrequencyHz;
    PlsrHostQueuedSetting[pulseOutput] = setting;
    *actualFrequencyHz = setting.actualFrequencyHz;
    PlsrPlatformExitCritical(criticalState);
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

void PlsrPlatformDrainPendingPulse(uint8_t pulseOutput)
{
    PlsrHostServicePendingPulse(pulseOutput);
}

uint32_t PlsrPlatformActiveFrequency(uint8_t pulseOutput)
{
    if (pulseOutput > 3U)
    {
        return 0UL;
    }
    return (PlsrHostFrequencyOffsetHz != 0L)
               ? PlsrHostOffsetFrequency(PlsrHostFrequency[pulseOutput])
               : PlsrHostFrequency[pulseOutput];
}

uint8_t PlsrPlatformExpectedFrequency(uint8_t pulseOutput,
                                      uint8_t outputMode,
                                      uint32_t requestedFrequencyHz,
                                      uint32_t *actualFrequencyHz)
{
    PLSR_PLATFORM_TIMER_SETTING setting;

    if (PlsrPlatformBuildTimerSetting(pulseOutput, outputMode,
                                      requestedFrequencyHz,
                                      &setting) == 0U)
    {
        return 0U;
    }
    *actualFrequencyHz = setting.actualFrequencyHz;
    return 1U;
}

uint64_t PlsrPlatformObservedPulses(uint8_t pulseOutput)
{
    int64_t observed;

    if (pulseOutput > 3U)
    {
        return 0UL;
    }
    observed = (int64_t)PlsrHostObservedPulses[pulseOutput]
               + (int64_t)PlsrHostCountOffset;
    return (observed > 0) ? (uint64_t)observed : 0UL;
}

uint16_t PlsrPlatformDiagnosticFault(void)
{
    uint16_t fault = PlsrHostDiagnosticFault;

    PlsrHostDiagnosticFault = 0U;
    return fault;
}

PLSR_PLATFORM_STOP_RESULT PlsrPlatformRequestStopLocked(
    uint8_t pulseOutput,
    uint8_t requireZeroBoundary)
{
    if (pulseOutput > 3U)
    {
        return PLSR_PLATFORM_STOP_FORCED_FAULT;
    }
    if (PlsrHostFailNextStopRequest != 0U)
    {
        PlsrHostFailNextStopRequest = 0U;
        PlsrPlatformStopPulse(pulseOutput);
        return PLSR_PLATFORM_STOP_FORCED_FAULT;
    }
    if ((requireZeroBoundary != 0U)
        && (PlsrHostOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        && (PlsrHostPulseActive[pulseOutput] != 0U)
        && (PlsrHostAbFastGated[pulseOutput] == 0U))
    {
        if (PlsrHostLatchAbFinalQuarterOnStopArm != 0U)
        {
            PlsrHostLatchAbFinalQuarterOnStopArm = 0U;
            (void)PlsrHostAdvanceAbQuarter(pulseOutput);
        }
        PlsrHostQueuedFrequency[pulseOutput] =
            PlsrHostFrequency[pulseOutput];
        PlsrHostAbStopPending[pulseOutput] = 1U;
        return PLSR_PLATFORM_STOP_PENDING;
    }
    PlsrPlatformStopPulse(pulseOutput);
    return PLSR_PLATFORM_STOP_COMPLETE;
}

uint8_t PlsrPlatformQueueFinalArmFromIrq(uint8_t pulseOutput)
{
    if ((pulseOutput > 2U) || ((pulseOutput & 1U) != 0U)
        || (PlsrHostOutputMode[pulseOutput] != PLSR_OUTPUT_AB)
        || (PlsrHostPulseActive[pulseOutput] == 0U)
        || (PlsrHostAbFastGated[pulseOutput] != 0U))
    {
        return 0U;
    }
    PlsrHostFinalArmJobOwner = pulseOutput;
    PlsrHostFinalArmJobPending = 1U;
    return 1U;
}

void PlsrPlatformStopPulse(uint8_t pulseOutput)
{
    if (pulseOutput <= 3U)
    {
        if ((PlsrHostOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
            && ((PlsrHostAbStopPending[pulseOutput] != 0U)
                || (PlsrHostAbFastGated[pulseOutput] != 0U)))
        {
            PlsrHostAbCleanupCount++;
        }
        PlsrHostPulseActive[pulseOutput] = 0U;
        PlsrHostFiniteActive[pulseOutput] = 0U;
        PlsrHostFiniteComplete[pulseOutput] = 0U;
        PlsrHostFrequency[pulseOutput] = 0UL;
        PlsrHostQueuedFrequency[pulseOutput] = 0UL;
        PlsrHostUpdatePending[pulseOutput] = 0U;
        PlsrHostAbQuarter[pulseOutput] = 0U;
        PlsrHostAbPhase[pulseOutput] = 0U;
        PlsrHostAbStopPending[pulseOutput] = 0U;
        PlsrHostAbFastGated[pulseOutput] = 0U;
        PlsrHostFrequencyOffsetHz = 0L;
        if (PlsrHostFinalArmJobOwner == pulseOutput)
        {
            PlsrHostFinalArmJobPending = 0U;
            PlsrHostFinalArmJobOwner = 0xFFU;
        }
    }
}

uint8_t PlsrPlatformReadInput(uint8_t inputSelection)
{
    return (inputSelection <= 1U) ? PlsrHostInputs[inputSelection] : 0U;
}

uint8_t PlsrPlatformLoad(PLSR_PERSIST_PAYLOAD *payload)
{
    if ((payload == NULL) || (PlsrHostPersistentValid == 0U))
    {
        return 0U;
    }
    *payload = PlsrHostPersistentPayload;
    return 1U;
}

void PlsrPlatformForceSafeOutputsFromFault(void)
{
    uint8_t index;

    for (index = 0U; index < 4U; index++)
    {
        PlsrPlatformStopPulse(index);
    }
}

PLSR_PLATFORM_SERVICE_RESULT PlsrPlatformServicePersistence(void)
{
    return PLSR_PLATFORM_SERVICE_READY;
}

uint8_t PlsrPlatformSave(const PLSR_PERSIST_PAYLOAD *payload)
{
    if (payload == NULL)
    {
        return 0U;
    }
    PlsrHostPersistentPayload = *payload;
    PlsrHostPersistentValid = 1U;
    PlsrHostSaveCount++;
    return 1U;
}

void PlsrPlatformCheckpointConfig(const PLSR_CONFIG *config)
{
    if (config != NULL)
    {
        PlsrHostPersistentPayload.config = *config;
        PlsrHostPersistentValid = 1U;
    }
}

void PlsrPlatformCheckpointPosition(int32_t position,
                                    uint8_t positionValid,
                                    uint8_t wasBusy)
{
    PlsrHostPersistentPayload.position = position;
    PlsrHostPersistentPayload.positionValid = positionValid;
    PlsrHostPersistentPayload.wasBusy = wasBusy;
    PlsrHostPersistentPayload.reserved = 0U;
}

uint32_t PlsrPlatformEnterCritical(void)
{
    uint32_t previousDepth = PlsrHostCriticalDepth;

    if (PlsrHostEmitPulseOnCriticalEntry != 0U)
    {
        if (PlsrHostCriticalEntriesToSkip != 0U)
        {
            PlsrHostCriticalEntriesToSkip--;
        }
        else
        {
            PlsrHostEmitPulseOnCriticalEntry = 0U;
            PlsrHostLatchPulse(PlsrHostSelectedPulse);
            if (previousDepth == 0UL)
            {
                PlsrHostServicePendingPulse(PlsrHostSelectedPulse);
            }
        }
    }
    if (PlsrHostLatchPulseOnCriticalEntry != 0U)
    {
        PlsrHostLatchPulseOnCriticalEntry = 0U;
        PlsrHostLatchPulse(PlsrHostSelectedPulse);
    }
    PlsrHostCriticalDepth++;
    return previousDepth;
}

void PlsrPlatformExitCritical(uint32_t state)
{
    (void)state;
    if (PlsrHostCriticalDepth != 0UL)
    {
        PlsrHostCriticalDepth--;
    }
    if (PlsrHostCriticalDepth != 0UL)
    {
        return;
    }
    if (PlsrHostEmitPulseOnCriticalExit != 0U)
    {
        PlsrHostEmitPulseOnCriticalExit = 0U;
        PlsrHostLatchPulse(PlsrHostSelectedPulse);
    }
    PlsrHostServicePendingPulse(PlsrHostSelectedPulse);
}

void PlsrTestSetInput(uint8_t inputSelection, uint8_t level)
{
    if (inputSelection <= 1U)
    {
        PlsrHostInputs[inputSelection] = (level != 0U) ? 1U : 0U;
    }
}

void PlsrTestEmitPulses(uint32_t pulseCount)
{
    if (PlsrHostFiniteActive[PlsrHostSelectedPulse] != 0U)
    {
        uint8_t pulseOutput = PlsrHostSelectedPulse;
        while ((pulseCount != 0UL)
               && (PlsrHostFiniteActive[pulseOutput] != 0U))
        {
            uint32_t available = PlsrHostFiniteTarget[pulseOutput]
                                 - PlsrHostFiniteEmitted[pulseOutput];
            uint32_t emitted = (pulseCount < available)
                                   ? pulseCount : available;

            if ((emitted != 0UL)
                && (PlsrHostFiniteFrequencyPending[pulseOutput] != 0U))
            {
                PlsrHostActiveSetting[pulseOutput] =
                    PlsrHostQueuedSetting[pulseOutput];
                PlsrHostFrequency[pulseOutput] =
                    PlsrHostQueuedFrequency[pulseOutput];
                PlsrHostFiniteFrequencyPending[pulseOutput] = 0U;
            }
            PlsrHostFiniteEmitted[pulseOutput] += emitted;
            PlsrHostObservedPulses[pulseOutput] += emitted;
            pulseCount -= emitted;
            if (PlsrHostFiniteEmitted[pulseOutput]
                == PlsrHostFiniteTarget[pulseOutput])
            {
                uint16_t index = PlsrHostFiniteStepIndex[pulseOutput];
                uint8_t hasNext = (index + 1U
                                   < PlsrHostFiniteStepCount[pulseOutput])
                                      ? 1U : 0U;

                if (PlsrHostFiniteStepCount[pulseOutput] != 0U)
                {
                    PlsrHostFiniteCompletedStepCount[pulseOutput] =
                        (uint16_t)(index + 1U);
                }
                if (hasNext != 0U)
                {
                    const PLSR_PLATFORM_FINITE_STEP *next =
                        &PlsrHostFiniteSteps[pulseOutput][index + 1U];

                    PlsrHostFiniteStepIndex[pulseOutput]++;
                    PlsrHostFiniteTarget[pulseOutput] = next->pulseCount;
                    PlsrHostFiniteEmitted[pulseOutput] = 0UL;
                    PlsrHostFrequency[pulseOutput] =
                        next->setting.actualFrequencyHz;
                    PlsrHostQueuedFrequency[pulseOutput] =
                        next->setting.actualFrequencyHz;
                    PlsrHostActiveSetting[pulseOutput] = next->setting;
                    PlsrHostQueuedSetting[pulseOutput] = next->setting;
                    PlsrHostFiniteFrequencyPending[pulseOutput] = 0U;
                }
                else
                {
                    PlsrHostFiniteActive[pulseOutput] = 0U;
                    PlsrHostFiniteComplete[pulseOutput] = 1U;
                    PlsrHostPulseActive[pulseOutput] = 0U;
                    PlsrHostFiniteFrequencyPending[pulseOutput] = 0U;
                    PlsrHostFrequency[pulseOutput] = 0UL;
                    PlsrHostQueuedFrequency[pulseOutput] = 0UL;
                }
            }
        }
        return;
    }
    if (PlsrHostOutputMode[PlsrHostSelectedPulse] == PLSR_OUTPUT_AB)
    {
        while ((pulseCount != 0UL)
               && (PlsrHostPulseActive[PlsrHostSelectedPulse] != 0U))
        {
            PlsrTestEmitAbQuarters(4UL);
            pulseCount--;
        }
        return;
    }
    while ((pulseCount != 0UL)
           && (PlsrHostPulseActive[PlsrHostSelectedPulse] != 0U))
    {
        PlsrHostLatchPulse(PlsrHostSelectedPulse);
        PlsrHostServicePendingPulse(PlsrHostSelectedPulse);
        pulseCount--;
    }
}

void PlsrTestEnableFinitePulseTrain(uint8_t enable)
{
    PlsrHostFiniteEnabled = (enable != 0U) ? 1U : 0U;
}

void PlsrTestCompleteFinitePulseTrain(void)
{
    uint8_t pulseOutput = PlsrHostSelectedPulse;

    if ((PlsrHostFiniteActive[pulseOutput] != 0U)
        && (PlsrHostPulseActive[pulseOutput] != 0U))
    {
        uint32_t remaining = PlsrHostFiniteTarget[pulseOutput]
                             - PlsrHostFiniteEmitted[pulseOutput];

        PlsrHostFiniteEmitted[pulseOutput] += remaining;
        PlsrHostObservedPulses[pulseOutput] += remaining;
        PlsrHostFiniteActive[pulseOutput] = 0U;
        PlsrHostFiniteComplete[pulseOutput] = 1U;
        PlsrHostPulseActive[pulseOutput] = 0U;
        PlsrHostFrequency[pulseOutput] = 0UL;
        PlsrHostQueuedFrequency[pulseOutput] = 0UL;
    }
}

uint8_t PlsrTestFinitePulseTrainActive(void)
{
    return PlsrHostFiniteActive[PlsrHostSelectedPulse];
}

void PlsrTestEmitPulseOnCriticalEntry(void)
{
    PlsrHostCriticalEntriesToSkip = 0U;
    PlsrHostEmitPulseOnCriticalEntry = 1U;
}

void PlsrTestEmitPulseAfterCriticalEntries(uint8_t entriesToSkip)
{
    PlsrHostCriticalEntriesToSkip = entriesToSkip;
    PlsrHostEmitPulseOnCriticalEntry = 1U;
}

void PlsrTestEmitPulseOnCriticalExit(void)
{
    PlsrHostEmitPulseOnCriticalExit = 1U;
}

void PlsrTestLatchPulseOnCriticalEntry(void)
{
    PlsrHostLatchPulseOnCriticalEntry = 1U;
}

void PlsrTestLatchAbFinalQuarterOnNextStopArm(void)
{
    PlsrHostLatchAbFinalQuarterOnStopArm = 1U;
}

void PlsrTestCompleteAbCycleOnNextQueueCommit(void)
{
    PlsrHostCompleteAbCycleOnQueueCommit = 1U;
}

void PlsrTestServicePendingPulse(void)
{
    PlsrHostServicePendingPulse(PlsrHostSelectedPulse);
}

void PlsrTestFailNextStart(void)
{
    PlsrHostFailNextStart = 1U;
}

void PlsrTestServiceFinalArmJob(void)
{
    PlsrHostServiceFinalArmJob();
}

void PlsrTestDeferFinalArmJob(uint8_t defer)
{
    PlsrHostDeferFinalArmJob = (defer != 0U) ? 1U : 0U;
    if (PlsrHostDeferFinalArmJob == 0U)
    {
        PlsrHostServiceFinalArmJob();
    }
}

void PlsrTestStaleNextFrequencyAtUpdate(void)
{
    PlsrHostStaleNextFrequencyAtUpdate = 1U;
}

void PlsrTestFailNextFrequencyAtUpdate(void)
{
    PlsrHostFailNextFrequencyAtUpdate = 1U;
}

void PlsrTestFailNextStopRequest(void)
{
    PlsrHostFailNextStopRequest = 1U;
}

void PlsrTestEmitAbQuarters(uint32_t quarterCount)
{
    uint8_t pulseOutput = PlsrHostSelectedPulse;

    while ((quarterCount != 0UL)
           && (PlsrHostPulseActive[pulseOutput] != 0U)
           && (PlsrHostOutputMode[pulseOutput] == PLSR_OUTPUT_AB))
    {
        if (PlsrHostAdvanceAbQuarter(pulseOutput) != 0U)
        {
            PlsrHostServicePendingPulse(pulseOutput);
        }
        quarterCount--;
    }
}

uint8_t PlsrTestPulseIsActive(void)
{
    return PlsrHostPulseActive[PlsrHostSelectedPulse];
}

uint32_t PlsrTestOutputFrequency(void)
{
    return PlsrHostFrequency[PlsrHostSelectedPulse];
}

uint32_t PlsrTestQueuedFrequency(void)
{
    return PlsrHostQueuedFrequency[PlsrHostSelectedPulse];
}

uint8_t PlsrTestDirectionLevel(void)
{
    return PlsrHostDirectionLevel;
}

uint8_t PlsrTestDirectionPinLevel(uint8_t directionOutput)
{
    return (directionOutput < 4U)
               ? PlsrHostDirectionPinLevel[directionOutput] : 0U;
}

uint32_t PlsrTestDirectionWriteCount(uint8_t directionOutput)
{
    return (directionOutput < 4U)
               ? PlsrHostDirectionWriteCount[directionOutput] : 0UL;
}

uint32_t PlsrTestDirectionTransitionCount(uint8_t directionOutput)
{
    return (directionOutput < 4U)
               ? PlsrHostDirectionTransitionCount[directionOutput] : 0UL;
}

uint8_t PlsrTestAbPhase(void)
{
    return PlsrHostAbPhase[PlsrHostSelectedPulse];
}

uint32_t PlsrTestAbTransitionCount(void)
{
    return PlsrHostAbTransitions[PlsrHostSelectedPulse];
}

uint32_t PlsrTestAbFastGateCount(void)
{
    return PlsrHostAbFastGateCount;
}

uint32_t PlsrTestAbCleanupCount(void)
{
    return PlsrHostAbCleanupCount;
}

void PlsrTestInjectCountOffset(int32_t offset)
{
    PlsrHostCountOffset = offset;
}

void PlsrTestInjectActiveFrequencyOffset(int32_t offsetHz)
{
    PlsrHostFrequencyOffsetHz = offsetHz;
    PlsrHostDiagnosticFault = 2U;
}

void PlsrTestInjectCurveMismatch(void)
{
    PlsrHostCurveMismatchPending = 1U;
}

void PlsrTestClearPersistentStorage(void)
{
    (void)memset(&PlsrHostPersistentPayload, 0,
                 sizeof(PlsrHostPersistentPayload));
    (void)memset(PlsrHostInputs, 0, sizeof(PlsrHostInputs));
    PlsrHostPersistentValid = 0U;
    PlsrHostSaveCount = 0UL;
    PlsrHostCountOffset = 0L;
    PlsrHostFrequencyOffsetHz = 0L;
    PlsrHostCurveMismatchPending = 0U;
    PlsrHostDiagnosticFault = 0U;
}

void PlsrTestResetSaveCount(void)
{
    PlsrHostSaveCount = 0UL;
}

uint32_t PlsrTestSaveCount(void)
{
    return PlsrHostSaveCount;
}

uint8_t PlsrTestFlashNeedsStartupRecovery(
    uint8_t haveValidRecord,
    uint8_t sectorAHasProgrammedSlot,
    uint32_t sectorAFirstErasedAddress,
    uint8_t sectorBHasProgrammedSlot,
    uint32_t sectorBFirstErasedAddress)
{
    return PlsrFlashNeedsStartupRecovery(
        haveValidRecord,
        sectorAHasProgrammedSlot,
        sectorAFirstErasedAddress,
        sectorBHasProgrammedSlot,
        sectorBFirstErasedAddress);
}

#else

#include "stm32f4xx_hal.h"
#include <stddef.h>
#include <string.h>

#ifndef PLSR_DEBUG_TIMING
#define PLSR_DEBUG_TIMING (0U)
#endif

#define PLSR_FLASH_SLOT_A_ADDRESS      (0x080C0000UL)
#define PLSR_FLASH_SLOT_B_ADDRESS      (0x080E0000UL)
#define PLSR_FLASH_SECTOR_SIZE          (0x00020000UL)
#define PLSR_FLASH_MAGIC               (0x50534C52UL)
#define PLSR_FLASH_VERSION_V2          (2U)
#define PLSR_FLASH_VERSION             (3U)
#define PLSR_BACKUP_CONFIG_ADDRESS     (BKPSRAM_BASE + 0x0100UL)
#define PLSR_BACKUP_POSITION_ADDRESS   (BKPSRAM_BASE + 0x0200UL)
#define PLSR_BACKUP_CONFIG_MAGIC       (0x50434647UL)
#define PLSR_BACKUP_POSITION_MAGIC     (0x50504F53UL)
#define PLSR_CONFIG_V2_SIZE            (offsetof(PLSR_CONFIG, outputMode))
#define PLSR_COUNTER_COUNT             (2U)
#define PLSR_COUNTER_NONE              (0xFFU)
#define PLSR_COUNTER_BLOCK_PULSES      (65536UL)
#define PLSR_PLATFORM_FAULT_FREQUENCY  (2U)
#define PLSR_PLATFORM_FAULT_CURVE      (3U)
#define PLSR_TIMER_OC1_MODE_MASK       (7UL << TIM_CCMR1_OC1M_Pos)
#define PLSR_TIMER_PWM1_MODE           (6UL << TIM_CCMR1_OC1M_Pos)
#define PLSR_STRUCTURE_VERIFY_INTERVAL (64U)
#define PLSR_FREQUENCY_VERIFY_NONE (0U)
#define PLSR_FREQUENCY_VERIFY_NOW (1U)
#define PLSR_FREQUENCY_VERIFY_AB_AUX_IRQ (2U)
#define PLSR_QUEUE_WRITE_GUARD_COUNTS  (64UL)
#define PLSR_FINITE_WRITE_GUARD_COUNTS (128UL)
#define PLSR_FLASH_ERASE_NONE          (0U)
#define PLSR_FLASH_ERASE_SECTOR_A      (1U)
#define PLSR_FLASH_ERASE_SECTOR_B      (2U)
#define PLSR_FLASH_ERASE_FAILED        (3U)

typedef struct
{
    TIM_TypeDef *timer;
    GPIO_TypeDef *port;
    uint16_t pin;
    uint8_t pinIndex;
    uint8_t alternate;
    IRQn_Type irq;
    uint32_t timerClockHz;
} PLSR_TIMER_MAP;

typedef struct
{
    GPIO_TypeDef *port;
    uint16_t pin;
} PLSR_GPIO_MAP;

typedef struct
{
    uint32_t prescaler;
    uint32_t period;
    uint32_t compare;
    uint32_t actualFrequencyHz;
} PLSR_TIMER_SETTING;

typedef struct
{
    uint32_t basePrescaler;
    uint32_t pairPrescaler;
    uint32_t period;
    uint32_t compare;
    uint32_t actualFrequencyHz;
} PLSR_AB_SETTING;

typedef struct
{
    uint32_t cr1;
    uint32_t ccmr1;
    uint32_t ccer;
    uint32_t psc;
    uint32_t arr;
    uint32_t ccr1;
} PLSR_TIMER_SNAPSHOT;

typedef struct
{
    uint32_t magic;
    uint16_t version;
    uint16_t payloadSize;
    uint32_t generation;
} PLSR_FLASH_HEADER;

typedef struct
{
    uint8_t config[PLSR_CONFIG_V2_SIZE];
    int32_t position;
    uint8_t positionValid;
    uint8_t wasBusy;
    uint16_t reserved;
} PLSR_PERSIST_PAYLOAD_V2;

typedef struct
{
    uint32_t magic;
    uint16_t version;
    uint16_t payloadSize;
    uint32_t generation;
    PLSR_PERSIST_PAYLOAD payload;
    uint32_t crc32;
} PLSR_FLASH_RECORD;

typedef struct
{
    uint32_t magic;
    uint16_t version;
    uint16_t payloadSize;
    uint32_t generation;
    PLSR_PERSIST_PAYLOAD_V2 payload;
    uint32_t crc32;
} PLSR_FLASH_RECORD_V2;

#define PLSR_FLASH_RECORD_STRIDE \
    ((uint32_t)sizeof(PLSR_FLASH_RECORD))
#define PLSR_FLASH_SLOT_COUNT \
    (PLSR_FLASH_SECTOR_SIZE / PLSR_FLASH_RECORD_STRIDE)

typedef char PLSR_FLASH_RECORD_SIZE_MUST_BE_228[
    (sizeof(PLSR_FLASH_RECORD) == 228U) ? 1 : -1];

typedef struct
{
    const PLSR_FLASH_HEADER *newest;
    uint32_t firstErasedAddress;
    uint8_t newestVersion;
    uint8_t hasProgrammedSlot;
} PLSR_FLASH_SECTOR_SCAN;

typedef struct
{
    uint32_t magic;
    PLSR_CONFIG config;
    uint32_t crc32;
} PLSR_BACKUP_CONFIG_RECORD;

typedef struct
{
    uint32_t magic;
    uint8_t config[PLSR_CONFIG_V2_SIZE];
    uint32_t crc32;
} PLSR_BACKUP_CONFIG_RECORD_V2;

typedef struct
{
    uint32_t magic;
    uint32_t generation;
    int32_t position;
    uint8_t positionValid;
    uint8_t wasBusy;
    uint16_t reserved;
    uint32_t crc32;
} PLSR_BACKUP_POSITION_RECORD;

static const PLSR_TIMER_MAP PlsrTimerMap[4] =
{
    {TIM10, GPIOF, GPIO_PIN_6, 6U, GPIO_AF3_TIM10,
     TIM1_UP_TIM10_IRQn, 168000000UL},
    {TIM13, GPIOF, GPIO_PIN_8, 8U, GPIO_AF9_TIM13,
     TIM8_UP_TIM13_IRQn, 84000000UL},
    {TIM11, GPIOF, GPIO_PIN_7, 7U, GPIO_AF3_TIM11,
     TIM1_TRG_COM_TIM11_IRQn, 168000000UL},
    {TIM14, GPIOF, GPIO_PIN_9, 9U, GPIO_AF9_TIM14,
     TIM8_TRG_COM_TIM14_IRQn, 84000000UL}
};

static const PLSR_GPIO_MAP PlsrDirectionMap[4] =
{
    {GPIOH, GPIO_PIN_9},
    {GPIOH, GPIO_PIN_8},
    {GPIOH, GPIO_PIN_7},
    {GPIOH, GPIO_PIN_6}
};

static PLSR_FLASH_RECORD PlsrFlashRecordBuffer;
static uint32_t PlsrFlashNewestAddress;
static uint32_t PlsrFlashNewestGeneration;
static uint32_t PlsrFlashNextErasedAddress[2];
static uint8_t PlsrFlashJournalInitialized;
static uint8_t PlsrFlashReserveEraseState;
static uint32_t PlsrBackupPositionGeneration;
static uint32_t PlsrTimerActiveFrequencyHz[4];
static uint32_t PlsrTimerQueuedFrequencyHz[4];
static PLSR_PLATFORM_TIMER_SETTING PlsrTimerActiveSetting[4];
static PLSR_PLATFORM_TIMER_SETTING PlsrTimerQueuedSetting[4];
static uint32_t PlsrTimerQueueGeneration[4];
static uint8_t PlsrTimerOutputMode[4];
static uint8_t PlsrTimerDirectionPositive[4];
static uint8_t PlsrTimerRunning[4];
static uint8_t PlsrFrequencyVerifyPending[4];
static uint8_t PlsrFrequencyVerifyPulseCount[4];
static volatile uint8_t PlsrDeferredPulsePending[4];
static volatile uint8_t PlsrAbVerifyOwner[4];
static volatile uint8_t PlsrAbFinalArmJobOwner[4];
static uint8_t PlsrTimerIrqActive[4];
static PLSR_AB_SETTING PlsrAbActiveSetting[4];
static PLSR_AB_SETTING PlsrAbPendingSetting[4];
static uint8_t PlsrAbFrequencyPending[4];
static uint8_t PlsrAbLagAxis[4];
static uint8_t PlsrAbStructureVerified[4];
static uint8_t PlsrAbCounterSourceAxis[4];
static uint32_t PlsrAbCounterBoundary[4];
static volatile uint8_t PlsrAbStopPending[4];
static volatile uint8_t PlsrAbFastGated[4];
static TIM_TypeDef * const PlsrCounters[PLSR_COUNTER_COUNT] =
{
    TIM9, TIM12
};
static uint8_t PlsrCounterOwner[PLSR_COUNTER_COUNT];
static volatile uint64_t PlsrCounterOverflowPulses[PLSR_COUNTER_COUNT];
static uint8_t PlsrCounterIndexByOutput[4];
static uint64_t PlsrObservedPulseBase[4];
static uint64_t PlsrObservedPulsePublished[4];
static volatile uint8_t PlsrFiniteActive[4];
static volatile uint8_t PlsrFiniteCompletionPending[4];
static volatile uint8_t PlsrFiniteFrequencyPending[4];
static volatile uint8_t PlsrFiniteRetargetPending[4];
static volatile uint8_t PlsrFiniteTailStopPending[4];
static uint32_t PlsrFiniteRetargetDrainPulses[4];
static uint32_t PlsrFiniteTargetPulses[4];
static uint32_t PlsrFiniteRemainingPulses[4];
static uint8_t PlsrFiniteCounterPreload[4];
static volatile uint8_t PlsrFiniteStreamActive[4];
static volatile uint8_t PlsrFiniteStreamNextValid[4];
static volatile uint8_t PlsrFiniteStreamNextStartsSegment[4];
static volatile uint8_t PlsrFiniteStreamSourceDone[4];
static volatile uint8_t PlsrFiniteStreamSourceFault[4];
static uint32_t PlsrFiniteStreamNextPulses[4];
static PLSR_PLATFORM_TIMER_SETTING PlsrFiniteStreamNextSetting[4];
static PLSR_PLATFORM_FINITE_STEP *PlsrFiniteSteps[4];
static volatile uint16_t PlsrFiniteStepCount[4];
static volatile uint16_t PlsrFiniteStepIndex[4];
static volatile uint16_t PlsrFiniteBoundaryReadIndex[4];
static volatile uint16_t PlsrFiniteCompletedStepCount[4];
static volatile uint16_t PlsrPlatformFaultPending;

static void PlsrHandleTimerIrq(uint8_t pulseOutput);
static void PlsrCounterSuspend(uint8_t pulseOutput);
static void PlsrAbFastGate(uint8_t pulseOutput);
static void PlsrFiniteCounterIrq(uint8_t pulseOutput,
                                 TIM_TypeDef *counter);
static void PlsrFinitePrepareNextStepIrq(uint8_t pulseOutput,
                                         TIM_TypeDef *counter);
static void PlsrFiniteArmNextStepPrepare(uint8_t pulseOutput,
                                         TIM_TypeDef *counter,
                                         uint32_t blockPulses);
static void PlsrFiniteRetargetAtFallingEdge(uint8_t pulseOutput);
static void PlsrFiniteStopAtFallingEdge(uint8_t pulseOutput);

static uint8_t PlsrFinalArmJobOutput(uint8_t pulseOutput)
{
    return (pulseOutput == 0U) ? 2U : 0U;
}

#if PLSR_DEBUG_TIMING
volatile uint32_t PlsrIrqCount[4];
volatile uint32_t PlsrIrqLastCycles[4];
volatile uint32_t PlsrIrqMaxCycles[4];
volatile uint32_t PlsrFinalArmQueueCount[4];
volatile uint32_t PlsrFinalArmJobLastCycles[4];
volatile uint32_t PlsrFinalArmJobMaxCycles[4];
volatile uint32_t PlsrFinalArmQueueToStopLastCycles[4];
volatile uint32_t PlsrFinalArmQueueToStopMaxCycles[4];
volatile uint32_t PlsrFiniteBlockIrqCount[4];
volatile uint32_t PlsrFiniteBlockIrqMaxCycles[4];
volatile uint32_t PlsrFiniteFinalIrqLastCycles[4];
volatile uint32_t PlsrFiniteFinalIrqMaxCycles[4];
volatile uint32_t PlsrAbReloadCounterBefore[4];
volatile uint32_t PlsrAbReloadCounterArmed[4];
volatile uint32_t PlsrAbReloadCounterStarted[4];
volatile uint32_t PlsrAbReloadCount[4];
static volatile uint32_t PlsrFinalArmQueuedAt[4];
static volatile uint8_t PlsrFinalArmQueueTimingPending[4];
#endif

static uint32_t PlsrCrc32(const void *data, uint32_t length)
{
    const uint8_t *bytes = (const uint8_t *)data;
    uint32_t crc = 0xFFFFFFFFUL;
    uint32_t index;
    uint8_t bit;

    for (index = 0UL; index < length; index++)
    {
        crc ^= bytes[index];
        for (bit = 0U; bit < 8U; bit++)
        {
            crc = ((crc & 1UL) != 0UL) ? ((crc >> 1U) ^ 0xEDB88320UL)
                                           : (crc >> 1U);
        }
    }
    return ~crc;
}

static uint8_t PlsrGenerationIsNewer(uint32_t first, uint32_t second)
{
    return ((int32_t)(first - second) > 0) ? 1U : 0U;
}

static uint32_t PlsrFlashRecordCrc(const void *record,
                                   uint32_t payloadSize)
{
    const PLSR_FLASH_HEADER *header = (const PLSR_FLASH_HEADER *)record;
    const uint8_t *start = (const uint8_t *)&header->version;
    uint32_t length = (uint32_t)(sizeof(header->version)
                                 + sizeof(header->payloadSize)
                                 + sizeof(header->generation))
                      + payloadSize;
    return PlsrCrc32(start, length);
}

static uint8_t PlsrFlashRecordVersion(const void *address)
{
    const PLSR_FLASH_HEADER *header = (const PLSR_FLASH_HEADER *)address;

    if (header->magic != PLSR_FLASH_MAGIC)
    {
        return 0U;
    }
    if ((header->version == PLSR_FLASH_VERSION)
        && (header->payloadSize == sizeof(PLSR_PERSIST_PAYLOAD)))
    {
        const PLSR_FLASH_RECORD *record =
            (const PLSR_FLASH_RECORD *)address;

        return (record->crc32
                == PlsrFlashRecordCrc(record, sizeof(record->payload)))
                   ? PLSR_FLASH_VERSION : 0U;
    }
    if ((header->version == PLSR_FLASH_VERSION_V2)
        && (header->payloadSize == sizeof(PLSR_PERSIST_PAYLOAD_V2)))
    {
        const PLSR_FLASH_RECORD_V2 *record =
            (const PLSR_FLASH_RECORD_V2 *)address;

        return (record->crc32
                == PlsrFlashRecordCrc(record, sizeof(record->payload)))
                   ? PLSR_FLASH_VERSION_V2 : 0U;
    }
    return 0U;
}

static uint8_t PlsrFlashSlotIsErased(uint32_t address)
{
    const uint32_t *words = (const uint32_t *)address;
    uint32_t index;

    for (index = 0UL;
         index < (PLSR_FLASH_RECORD_STRIDE / sizeof(uint32_t));
         index++)
    {
        if (words[index] != 0xFFFFFFFFUL)
        {
            return 0U;
        }
    }
    return 1U;
}

static uint8_t PlsrFlashSectorIsErased(uint32_t address)
{
    const uint32_t *words = (const uint32_t *)address;
    uint32_t index;

    for (index = 0UL;
         index < (PLSR_FLASH_SECTOR_SIZE / sizeof(uint32_t)); index++)
    {
        if (words[index] != 0xFFFFFFFFUL)
        {
            return 0U;
        }
    }
    return 1U;
}

static void PlsrFlashScanSector(uint32_t sectorAddress,
                                PLSR_FLASH_SECTOR_SCAN *scan)
{
    uint32_t index;

    (void)memset(scan, 0, sizeof(*scan));
    for (index = 0UL; index < PLSR_FLASH_SLOT_COUNT; index++)
    {
        uint32_t slotAddress = sectorAddress
                               + index * PLSR_FLASH_RECORD_STRIDE;
        const PLSR_FLASH_HEADER *header =
            (const PLSR_FLASH_HEADER *)slotAddress;
        uint8_t version = PlsrFlashRecordVersion(header);
        uint8_t erased = PlsrFlashSlotIsErased(slotAddress);

        if ((version != 0U)
            && ((scan->newest == NULL)
                || (PlsrGenerationIsNewer(header->generation,
                                          scan->newest->generation) != 0U)))
        {
            scan->newest = header;
            scan->newestVersion = version;
        }
        if ((scan->firstErasedAddress == 0UL) && (erased != 0U))
        {
            scan->firstErasedAddress = slotAddress;
        }
        if (erased == 0U)
        {
            scan->hasProgrammedSlot = 1U;
        }
    }
    for (index = PLSR_FLASH_SLOT_COUNT * PLSR_FLASH_RECORD_STRIDE;
         index < PLSR_FLASH_SECTOR_SIZE; index += sizeof(uint32_t))
    {
        if (*(const uint32_t *)(sectorAddress + index) != 0xFFFFFFFFUL)
        {
            scan->hasProgrammedSlot = 1U;
        }
    }
}

static const PLSR_FLASH_HEADER *PlsrFlashSelectNewest(
    const PLSR_FLASH_SECTOR_SCAN *scanA,
    const PLSR_FLASH_SECTOR_SCAN *scanB,
    uint8_t *version,
    uint32_t *sectorAddress)
{
    const PLSR_FLASH_SECTOR_SCAN *selectedScan;

    if (scanA->newest == NULL)
    {
        selectedScan = (scanB->newest != NULL) ? scanB : NULL;
    }
    else if ((scanB->newest != NULL)
             && (PlsrGenerationIsNewer(scanB->newest->generation,
                                       scanA->newest->generation) != 0U))
    {
        selectedScan = scanB;
    }
    else
    {
        selectedScan = scanA;
    }

    if (selectedScan == NULL)
    {
        *version = 0U;
        *sectorAddress = 0UL;
        return NULL;
    }
    *version = selectedScan->newestVersion;
    *sectorAddress = (selectedScan == scanA)
                         ? PLSR_FLASH_SLOT_A_ADDRESS
                         : PLSR_FLASH_SLOT_B_ADDRESS;
    return selectedScan->newest;
}

static const PLSR_FLASH_HEADER *PlsrFlashInitializeJournal(
    PLSR_FLASH_SECTOR_SCAN *scanA,
    PLSR_FLASH_SECTOR_SCAN *scanB,
    uint8_t *version,
    uint32_t *sectorAddress)
{
    const PLSR_FLASH_HEADER *newest;

    PlsrFlashScanSector(PLSR_FLASH_SLOT_A_ADDRESS, scanA);
    PlsrFlashScanSector(PLSR_FLASH_SLOT_B_ADDRESS, scanB);
    newest = PlsrFlashSelectNewest(scanA, scanB, version, sectorAddress);
    PlsrFlashNextErasedAddress[0] = scanA->firstErasedAddress;
    PlsrFlashNextErasedAddress[1] = scanB->firstErasedAddress;
    PlsrFlashNewestAddress = (uint32_t)newest;
    PlsrFlashNewestGeneration = (newest != NULL)
                                    ? newest->generation : 0UL;
    PlsrFlashJournalInitialized = 1U;
    return newest;
}

static uint8_t PlsrFlashSectorIndex(uint32_t address)
{
    return (address >= PLSR_FLASH_SLOT_B_ADDRESS) ? 1U : 0U;
}

static uint8_t PlsrFlashAddressIsJournalSlot(uint8_t sectorIndex,
                                             uint32_t address)
{
    uint32_t sectorAddress = (sectorIndex == 0U)
                                 ? PLSR_FLASH_SLOT_A_ADDRESS
                                 : PLSR_FLASH_SLOT_B_ADDRESS;
    uint32_t offset;

    if ((address < sectorAddress)
        || (address >= sectorAddress + PLSR_FLASH_SECTOR_SIZE))
    {
        return 0U;
    }
    offset = address - sectorAddress;
    return ((offset % PLSR_FLASH_RECORD_STRIDE) == 0UL)
               && ((offset / PLSR_FLASH_RECORD_STRIDE)
                   < PLSR_FLASH_SLOT_COUNT) ? 1U : 0U;
}

static uint32_t PlsrFlashFindErasedAfter(uint8_t sectorIndex,
                                         uint32_t address)
{
    uint32_t sectorAddress = (sectorIndex == 0U)
                                 ? PLSR_FLASH_SLOT_A_ADDRESS
                                 : PLSR_FLASH_SLOT_B_ADDRESS;
    uint32_t firstIndex = ((address - sectorAddress)
                           / PLSR_FLASH_RECORD_STRIDE) + 1UL;
    uint32_t index;

    for (index = firstIndex; index < PLSR_FLASH_SLOT_COUNT; index++)
    {
        uint32_t slotAddress = sectorAddress
                               + index * PLSR_FLASH_RECORD_STRIDE;

        if (PlsrFlashSlotIsErased(slotAddress) != 0U)
        {
            return slotAddress;
        }
    }
    return 0UL;
}

static uint8_t PlsrFlashEraseReserve(uint8_t sectorIndex)
{
    FLASH_EraseInitTypeDef erase;
    uint32_t sectorError;
    HAL_StatusTypeDef status;

    if (HAL_FLASH_Unlock() != HAL_OK)
    {
        (void)HAL_FLASH_Lock();
        return 0U;
    }
    __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR
                           | FLASH_FLAG_PGAERR | FLASH_FLAG_PGPERR
                           | FLASH_FLAG_PGSERR);
    erase.TypeErase = FLASH_TYPEERASE_SECTORS;
    erase.VoltageRange = FLASH_VOLTAGE_RANGE_3;
    erase.Sector = (sectorIndex == 0U) ? FLASH_SECTOR_10 : FLASH_SECTOR_11;
    erase.NbSectors = 1U;
    status = HAL_FLASHEx_Erase(&erase, &sectorError);
    if ((status == HAL_OK)
        && (PlsrFlashSectorIsErased((sectorIndex == 0U)
                                        ? PLSR_FLASH_SLOT_A_ADDRESS
                                        : PLSR_FLASH_SLOT_B_ADDRESS) == 0U))
    {
        status = HAL_ERROR;
    }
    if (HAL_FLASH_Lock() != HAL_OK)
    {
        (void)HAL_FLASH_Lock();
        status = HAL_ERROR;
    }
    return (status == HAL_OK) ? 1U : 0U;
}

static uint8_t PlsrBackupConfigVersion(const void *address)
{
    const PLSR_BACKUP_CONFIG_RECORD *record =
        (const PLSR_BACKUP_CONFIG_RECORD *)address;

    if (record->magic != PLSR_BACKUP_CONFIG_MAGIC)
    {
        return 0U;
    }
    if (record->crc32 == PlsrCrc32(&record->config, sizeof(record->config)))
    {
        return PLSR_FLASH_VERSION;
    }
    {
        const PLSR_BACKUP_CONFIG_RECORD_V2 *oldRecord =
            (const PLSR_BACKUP_CONFIG_RECORD_V2 *)address;

        return (oldRecord->crc32
                == PlsrCrc32(oldRecord->config, sizeof(oldRecord->config)))
                   ? PLSR_FLASH_VERSION_V2 : 0U;
    }
}

static void PlsrLoadV2Payload(PLSR_PERSIST_PAYLOAD *destination,
                              const PLSR_PERSIST_PAYLOAD_V2 *source)
{
    (void)memset(destination, 0, sizeof(*destination));
    (void)memcpy(&destination->config, source->config,
                 sizeof(source->config));
    destination->config.outputMode = PLSR_OUTPUT_PULSE_DIR;
    destination->position = source->position;
    destination->positionValid = source->positionValid;
    destination->wasBusy = source->wasBusy;
}

static uint8_t PlsrBackupPositionIsValid(
    const PLSR_BACKUP_POSITION_RECORD *record)
{
    uint32_t crc = PlsrCrc32(&record->generation,
                             sizeof(record->generation)
                             + sizeof(record->position)
                             + sizeof(record->positionValid)
                             + sizeof(record->wasBusy)
                             + sizeof(record->reserved));
    return ((record->magic == PLSR_BACKUP_POSITION_MAGIC)
            && (record->crc32 == crc)) ? 1U : 0U;
}

static const PLSR_BACKUP_POSITION_RECORD *PlsrNewestBackupPosition(void)
{
    const PLSR_BACKUP_POSITION_RECORD *slots =
        (const PLSR_BACKUP_POSITION_RECORD *)PLSR_BACKUP_POSITION_ADDRESS;
    uint8_t validA = PlsrBackupPositionIsValid(&slots[0]);
    uint8_t validB = PlsrBackupPositionIsValid(&slots[1]);

    if ((validA == 0U) && (validB == 0U))
    {
        return NULL;
    }
    if (validA == 0U)
    {
        return &slots[1];
    }
    if (validB == 0U)
    {
        return &slots[0];
    }
    return (PlsrGenerationIsNewer(slots[1].generation,
                                  slots[0].generation) != 0U)
               ? &slots[1] : &slots[0];
}

static void PlsrTimerStop(TIM_TypeDef *timer)
{
    timer->DIER &= ~(TIM_DIER_UIE | TIM_DIER_CC1IE);
    timer->CR1 &= ~TIM_CR1_CEN;
    timer->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
    timer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
}

static void PlsrTimerInitialize(TIM_TypeDef *timer)
{
    timer->CR1 = TIM_CR1_ARPE | TIM_CR1_URS;
    timer->CR2 = 0UL;
    timer->SMCR = 0UL;
    timer->DIER = 0UL;
    timer->CCMR1 = TIM_CCMR1_OC1PE | (6UL << TIM_CCMR1_OC1M_Pos);
    timer->CCER = 0UL;
    timer->PSC = 0UL;
    timer->ARR = 999UL;
    timer->CCR1 = 500UL;
    timer->CNT = 0UL;
    timer->EGR = TIM_EGR_UG;
    timer->SR = 0UL;
}

static void PlsrPulsePinHoldIdle(uint8_t pulseOutput)
{
    const PLSR_TIMER_MAP *map = &PlsrTimerMap[pulseOutput];
    GPIO_InitTypeDef gpio;

    HAL_GPIO_WritePin(map->port, map->pin, GPIO_PIN_SET);
    gpio.Pin = map->pin;
    gpio.Mode = GPIO_MODE_OUTPUT_PP;
    gpio.Pull = GPIO_NOPULL;
    gpio.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    gpio.Alternate = 0U;
    HAL_GPIO_Init(map->port, &gpio);
}

static void PlsrPulsePinCaptureIdle(uint8_t pulseOutput)
{
    const PLSR_TIMER_MAP *map = &PlsrTimerMap[pulseOutput];
    uint32_t shift = (uint32_t)map->pinIndex * 2UL;
    uint32_t mode = map->port->MODER;

    /* The update IRQ occurs while PWM is high; switch to GPIO high first. */
    map->port->BSRR = map->pin;
    mode &= ~(3UL << shift);
    mode |= 1UL << shift;
    map->port->MODER = mode;
    __DSB();
}

static void PlsrPulsePinRelease(uint8_t pulseOutput)
{
    const PLSR_TIMER_MAP *map = &PlsrTimerMap[pulseOutput];
    GPIO_InitTypeDef gpio;

    gpio.Pin = map->pin;
    gpio.Mode = GPIO_MODE_AF_PP;
    gpio.Pull = GPIO_NOPULL;
    gpio.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    gpio.Alternate = map->alternate;
    HAL_GPIO_Init(map->port, &gpio);
    __DSB();
}

static uint8_t PlsrTimerCalculate(uint8_t pulseOutput,
                                  uint32_t frequencyHz,
                                  PLSR_TIMER_SETTING *setting)
{
    const PLSR_TIMER_MAP *map;
    uint32_t prescalerDivider;
    uint32_t denominator;
    uint32_t periodCounts;

    if ((pulseOutput > 3U) || (frequencyHz == 0UL)
        || (frequencyHz > PLSR_FREQUENCY_MAX_HZ)
        || (setting == NULL))
    {
        return 0U;
    }

    map = &PlsrTimerMap[pulseOutput];
    prescalerDivider = (((map->timerClockHz - 1UL) / frequencyHz) >> 16U)
                       + 1UL;
    if (prescalerDivider > 65536UL)
    {
        return 0U;
    }
    denominator = prescalerDivider * frequencyHz;
    periodCounts = (map->timerClockHz + denominator / 2UL) / denominator;
    if (periodCounts < 2UL)
    {
        periodCounts = 2UL;
    }
    if (periodCounts > 65536UL)
    {
        periodCounts = 65536UL;
    }

    setting->prescaler = prescalerDivider - 1UL;
    setting->period = periodCounts - 1UL;
    setting->compare = periodCounts / 2UL;
    denominator = prescalerDivider * periodCounts;
    setting->actualFrequencyHz =
        (map->timerClockHz + denominator / 2UL) / denominator;
    return 1U;
}

static void PlsrTimerWriteSetting(TIM_TypeDef *timer,
                                  const PLSR_TIMER_SETTING *setting)
{
    timer->PSC = setting->prescaler;
    timer->ARR = setting->period;
    timer->CCR1 = setting->compare;
}

static void PlsrTimerSnapshot(TIM_TypeDef *timer,
                              PLSR_TIMER_SNAPSHOT *snapshot)
{
    snapshot->cr1 = timer->CR1;
    snapshot->ccmr1 = timer->CCMR1;
    snapshot->ccer = timer->CCER;
    snapshot->psc = timer->PSC;
    snapshot->arr = timer->ARR;
    snapshot->ccr1 = timer->CCR1;
}

static uint8_t PlsrAbCalculate(uint8_t pulseOutput,
                               uint32_t frequencyHz,
                               PLSR_AB_SETTING *setting)
{
    const PLSR_TIMER_MAP *baseMap;
    const PLSR_TIMER_MAP *pairMap;
    uint64_t ratio;
    uint64_t pairDivider;
    uint64_t baseDivider;
    uint64_t periodCounts;

    if (((pulseOutput != 0U) && (pulseOutput != 2U))
        || (frequencyHz == 0UL)
        || (frequencyHz > PLSR_FREQUENCY_MAX_HZ)
        || (setting == NULL))
    {
        return 0U;
    }
    baseMap = &PlsrTimerMap[pulseOutput];
    pairMap = &PlsrTimerMap[pulseOutput + 1U];
    if ((pairMap->timerClockHz == 0UL)
        || ((baseMap->timerClockHz % pairMap->timerClockHz) != 0UL))
    {
        return 0U;
    }
    ratio = baseMap->timerClockHz / pairMap->timerClockHz;
    pairDivider = ((uint64_t)pairMap->timerClockHz
                   + (uint64_t)frequencyHz * 65536UL - 1UL)
                  / ((uint64_t)frequencyHz * 65536UL);
    if (pairDivider == 0UL)
    {
        pairDivider = 1UL;
    }
    baseDivider = pairDivider * ratio;
    if ((pairDivider > 65536UL) || (baseDivider > 65536UL))
    {
        return 0U;
    }
    periodCounts = ((uint64_t)pairMap->timerClockHz
                    + ((uint64_t)frequencyHz * pairDivider) / 2UL)
                   / ((uint64_t)frequencyHz * pairDivider);
    if ((periodCounts < 4UL) || (periodCounts > 65536UL))
    {
        return 0U;
    }
    setting->basePrescaler = (uint32_t)(baseDivider - 1UL);
    setting->pairPrescaler = (uint32_t)(pairDivider - 1UL);
    setting->period = (uint32_t)(periodCounts - 1UL);
    setting->compare = (uint32_t)(periodCounts / 2UL);
    setting->actualFrequencyHz =
        (uint32_t)(((uint64_t)pairMap->timerClockHz
                    + (pairDivider * periodCounts) / 2UL)
                   / (pairDivider * periodCounts));
    return 1U;
}

static void PlsrAbHoldPairIdle(uint8_t pulseOutput)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    GPIO_TypeDef *port = PlsrTimerMap[pulseOutput].port;
    uint32_t firstShift = (uint32_t)PlsrTimerMap[pulseOutput].pinIndex * 2UL;
    uint32_t secondShift = (uint32_t)PlsrTimerMap[pairOutput].pinIndex * 2UL;
    uint32_t mode = port->MODER;

    port->BSRR = (uint32_t)PlsrTimerMap[pulseOutput].pin
                 | (uint32_t)PlsrTimerMap[pairOutput].pin;
    mode &= ~((3UL << firstShift) | (3UL << secondShift));
    mode |= (1UL << firstShift) | (1UL << secondShift);
    port->MODER = mode;
    __DSB();
}

static void PlsrAbReleasePair(uint8_t pulseOutput)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    GPIO_TypeDef *port = PlsrTimerMap[pulseOutput].port;
    uint32_t firstAfrIndex =
        (uint32_t)PlsrTimerMap[pulseOutput].pinIndex >> 3U;
    uint32_t secondAfrIndex =
        (uint32_t)PlsrTimerMap[pairOutput].pinIndex >> 3U;
    uint32_t firstAfrShift =
        ((uint32_t)PlsrTimerMap[pulseOutput].pinIndex & 7UL) * 4UL;
    uint32_t secondAfrShift =
        ((uint32_t)PlsrTimerMap[pairOutput].pinIndex & 7UL) * 4UL;
    uint32_t firstShift = (uint32_t)PlsrTimerMap[pulseOutput].pinIndex * 2UL;
    uint32_t secondShift = (uint32_t)PlsrTimerMap[pairOutput].pinIndex * 2UL;
    uint32_t alternate;
    uint32_t mode = port->MODER;

    alternate = port->AFR[firstAfrIndex];
    alternate &= ~(0xFUL << firstAfrShift);
    alternate |= (uint32_t)PlsrTimerMap[pulseOutput].alternate
                 << firstAfrShift;
    port->AFR[firstAfrIndex] = alternate;
    alternate = port->AFR[secondAfrIndex];
    alternate &= ~(0xFUL << secondAfrShift);
    alternate |= (uint32_t)PlsrTimerMap[pairOutput].alternate
                 << secondAfrShift;
    port->AFR[secondAfrIndex] = alternate;
    mode &= ~((3UL << firstShift) | (3UL << secondShift));
    mode |= (2UL << firstShift) | (2UL << secondShift);
    port->MODER = mode;
    __DSB();
}

static uint8_t PlsrAbStructureIsRunnable(
    uint8_t pulseOutput,
    const PLSR_TIMER_SNAPSHOT *base,
    const PLSR_TIMER_SNAPSHOT *pair)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    uint8_t lagOutput = PlsrAbLagAxis[pulseOutput];

    return ((((base->cr1 & TIM_CR1_CEN) != 0UL)
             && ((pair->cr1 & TIM_CR1_CEN) != 0UL)
             && ((base->ccer & TIM_CCER_CC1E) != 0UL)
             && ((pair->ccer & TIM_CCER_CC1E) != 0UL)
             && ((base->ccer & TIM_CCER_CC1P) != 0UL)
             && ((pair->ccer & TIM_CCER_CC1P) != 0UL)
             && ((base->ccmr1 & PLSR_TIMER_OC1_MODE_MASK)
                 == PLSR_TIMER_PWM1_MODE)
             && ((pair->ccmr1 & PLSR_TIMER_OC1_MODE_MASK)
                 == PLSR_TIMER_PWM1_MODE)
             && (base->arr == pair->arr)
             && (base->ccr1 == pair->ccr1)
             && (base->ccr1 == ((base->arr + 1UL) / 2UL))
             && ((base->psc + 1UL) == 2UL * (pair->psc + 1UL))
             && ((lagOutput == pulseOutput) || (lagOutput == pairOutput)))
                 ? 1U : 0U);
}

static uint8_t PlsrAbTimersAreRunnable(uint8_t pulseOutput,
                                       TIM_TypeDef *baseTimer,
                                       TIM_TypeDef *pairTimer)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    uint8_t lagOutput = PlsrAbLagAxis[pulseOutput];
    uint32_t baseCr1 = baseTimer->CR1;
    uint32_t pairCr1 = pairTimer->CR1;
    uint32_t baseCcer = baseTimer->CCER;
    uint32_t pairCcer = pairTimer->CCER;
    uint32_t baseCcmr1 = baseTimer->CCMR1;
    uint32_t pairCcmr1 = pairTimer->CCMR1;
    uint32_t basePsc = baseTimer->PSC;
    uint32_t pairPsc = pairTimer->PSC;
    uint32_t baseCcr1 = baseTimer->CCR1;
    uint32_t pairCcr1 = pairTimer->CCR1;
    uint32_t baseArr = baseTimer->ARR;
    uint32_t pairArr = pairTimer->ARR;

    return (((((baseCr1 & TIM_CR1_CEN) != 0UL)
              && ((pairCr1 & TIM_CR1_CEN) != 0UL)
              && ((baseCcer & (TIM_CCER_CC1E | TIM_CCER_CC1P))
                  == (TIM_CCER_CC1E | TIM_CCER_CC1P))
              && ((pairCcer & (TIM_CCER_CC1E | TIM_CCER_CC1P))
                  == (TIM_CCER_CC1E | TIM_CCER_CC1P))
              && ((baseCcmr1 & PLSR_TIMER_OC1_MODE_MASK)
                  == PLSR_TIMER_PWM1_MODE)
              && ((pairCcmr1 & PLSR_TIMER_OC1_MODE_MASK)
                  == PLSR_TIMER_PWM1_MODE)
              && (baseArr == pairArr)
              && (baseCcr1 == pairCcr1)
              && (baseCcr1 == ((baseArr + 1UL) / 2UL))
              && ((basePsc + 1UL) == 2UL * (pairPsc + 1UL))
              && ((lagOutput == pulseOutput)
                  || (lagOutput == pairOutput))) ? 1U : 0U));
}

static uint8_t PlsrAbStopBoundaryIsReachable(
    uint8_t pulseOutput,
    TIM_TypeDef *baseTimer,
    TIM_TypeDef *pairTimer)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    uint8_t lagOutput = PlsrAbLagAxis[pulseOutput];
    uint32_t baseCr1 = baseTimer->CR1;
    uint32_t pairCr1 = pairTimer->CR1;
    uint32_t baseCcer = baseTimer->CCER;
    uint32_t pairCcer = pairTimer->CCER;
    uint32_t baseCcr1 = baseTimer->CCR1;
    uint32_t pairCcr1 = pairTimer->CCR1;
    uint32_t baseArr = baseTimer->ARR;
    uint32_t pairArr = pairTimer->ARR;

    return (((((baseCr1 & TIM_CR1_CEN) != 0UL)
              && ((pairCr1 & TIM_CR1_CEN) != 0UL)
              && ((baseCcer & TIM_CCER_CC1E) != 0UL)
              && ((pairCcer & TIM_CCER_CC1E) != 0UL)
              && (baseCcr1 <= baseArr)
              && (pairCcr1 <= pairArr)
              && ((lagOutput == pulseOutput)
                  || (lagOutput == pairOutput))) ? 1U : 0U));
}

static void PlsrAbFastGate(uint8_t pulseOutput)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    TIM_TypeDef *baseTimer = PlsrTimerMap[pulseOutput].timer;
    TIM_TypeDef *pairTimer = PlsrTimerMap[pairOutput].timer;

    PlsrAbStructureVerified[pulseOutput] = 0U;
    baseTimer->CR1 &= ~TIM_CR1_CEN;
    pairTimer->CR1 &= ~TIM_CR1_CEN;
    PlsrCounterSuspend(pulseOutput);
    __DMB();
}

#if defined(__ICCARM__)
#pragma inline=never
#endif
static void PlsrAbEnableTimerPair(TIM_TypeDef *firstTimer,
                                  uint32_t firstCr1,
                                  TIM_TypeDef *secondTimer,
                                  uint32_t secondCr1)
{
    firstTimer->CR1 = firstCr1;
    secondTimer->CR1 = secondCr1;
}

static uint8_t PlsrAbCanFastGateAtZero(uint8_t pulseOutput)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    TIM_TypeDef *baseTimer = PlsrTimerMap[pulseOutput].timer;
    TIM_TypeDef *pairTimer = PlsrTimerMap[pairOutput].timer;
    uint32_t baseCr1 = baseTimer->CR1;
    uint32_t pairCr1 = pairTimer->CR1;
    uint32_t baseCcer = baseTimer->CCER;
    uint32_t pairCcer = pairTimer->CCER;
    uint32_t baseCcr = baseTimer->CCR1;
    uint32_t pairCcr = pairTimer->CCR1;
    uint32_t baseCnt = baseTimer->CNT;
    uint32_t pairCnt = pairTimer->CNT;

    return ((((baseCr1 & TIM_CR1_CEN) != 0UL)
             && ((pairCr1 & TIM_CR1_CEN) != 0UL)
             && ((baseCcer & TIM_CCER_CC1E) != 0UL)
             && ((pairCcer & TIM_CCER_CC1E) != 0UL)
             && (baseCnt >= baseCcr)
             && (pairCnt >= pairCcr)) ? 1U : 0U);
}

static uint8_t PlsrCounterIndex(uint8_t pulseOutput, uint8_t outputMode)
{
    return (outputMode == PLSR_OUTPUT_AB)
               ? (uint8_t)(pulseOutput >> 1U)
               : (uint8_t)(pulseOutput & 1U);
}

static uint64_t PlsrCounterCurrentRaw(uint8_t pulseOutput)
{
    uint8_t index = PlsrCounterIndexByOutput[pulseOutput];
    TIM_TypeDef *counter;
    uint64_t overflowBefore;
    uint64_t overflowAfter;
    uint32_t statusBefore;
    uint32_t statusAfter;
    uint32_t count;

    if (index >= PLSR_COUNTER_COUNT)
    {
        return 0UL;
    }
    counter = PlsrCounters[index];
    for (;;)
    {
        overflowBefore = PlsrCounterOverflowPulses[index];
        statusBefore = counter->SR & TIM_SR_UIF;
        count = (uint16_t)counter->CNT;
        statusAfter = counter->SR & TIM_SR_UIF;
        overflowAfter = PlsrCounterOverflowPulses[index];
        if ((overflowBefore == overflowAfter)
            && (statusBefore == statusAfter))
        {
            if (statusAfter != 0UL)
            {
                overflowAfter += PLSR_COUNTER_BLOCK_PULSES;
            }
            return overflowAfter + count;
        }
    }
}

static uint64_t PlsrCounterSnapshot(uint8_t pulseOutput)
{
    uint64_t current = PlsrCounterCurrentRaw(pulseOutput);
    uint64_t observed;

    if ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        && (current > 0UL))
    {
        uint8_t sourceAxis = PlsrAbCounterSourceAxis[pulseOutput];
        uint8_t attempt;

        for (attempt = 0U; attempt < 2U; attempt++)
        {
            uint64_t verified;

            current = PlsrCounterCurrentRaw(pulseOutput);
            if (sourceAxis <= 3U)
            {
                uint32_t sourceCount = PlsrTimerMap[sourceAxis].timer->CNT;

                verified = PlsrCounterCurrentRaw(pulseOutput);
                if (current == verified)
                {
                    if ((sourceCount
                         < PlsrAbCounterBoundary[pulseOutput])
                        && (current > 0UL))
                    {
                        current--;
                    }
                    break;
                }
                current = verified;
            }
        }
    }
    observed = PlsrObservedPulseBase[pulseOutput] + current;
    if (observed < PlsrObservedPulsePublished[pulseOutput])
    {
        observed = PlsrObservedPulsePublished[pulseOutput];
    }
    else
    {
        PlsrObservedPulsePublished[pulseOutput] = observed;
    }
    return observed;
}

static uint64_t PlsrCounterSnapshotStopped(uint8_t pulseOutput)
{
    uint8_t index = PlsrCounterIndexByOutput[pulseOutput];
    TIM_TypeDef *counter = PlsrCounters[index];
    uint64_t current = PlsrCounterOverflowPulses[index];
    uint64_t observed;

    current += (uint16_t)counter->CNT;
    if ((counter->SR & TIM_SR_UIF) != 0UL)
    {
        current += PLSR_COUNTER_BLOCK_PULSES;
    }
    if ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        && (current > 0UL))
    {
        uint8_t sourceAxis = PlsrAbCounterSourceAxis[pulseOutput];

        if ((sourceAxis <= 3U)
            && (PlsrTimerMap[sourceAxis].timer->CNT
                < PlsrAbCounterBoundary[pulseOutput]))
        {
            current--;
        }
    }
    observed = PlsrObservedPulseBase[pulseOutput] + current;
    if (observed < PlsrObservedPulsePublished[pulseOutput])
    {
        observed = PlsrObservedPulsePublished[pulseOutput];
    }
    else
    {
        PlsrObservedPulsePublished[pulseOutput] = observed;
    }
    return observed;
}

static void PlsrCounterStop(uint8_t pulseOutput)
{
    uint8_t index = PlsrCounterIndexByOutput[pulseOutput];

    if (index < PLSR_COUNTER_COUNT)
    {
        TIM_TypeDef *counter = PlsrCounters[index];

        if ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
            && (PlsrAbFastGated[pulseOutput] != 0U))
        {
            PlsrObservedPulseBase[pulseOutput] =
                PlsrCounterSnapshotStopped(pulseOutput);
        }
        else
        {
            PlsrCounterSuspend(pulseOutput);
            PlsrObservedPulseBase[pulseOutput] =
                PlsrCounterSnapshot(pulseOutput);
        }
        PlsrObservedPulsePublished[pulseOutput] =
            PlsrObservedPulseBase[pulseOutput];

        counter->CR1 = 0UL;
        counter->DIER = 0UL;
        counter->SMCR = 0UL;
        counter->SR = 0UL;
        if (PlsrCounterOwner[index] == pulseOutput)
        {
            PlsrCounterOwner[index] = PLSR_COUNTER_NONE;
        }
    }
    PlsrCounterIndexByOutput[pulseOutput] = PLSR_COUNTER_NONE;
}

static uint8_t PlsrCounterConfigure(uint8_t pulseOutput, uint8_t outputMode)
{
    uint8_t index = PlsrCounterIndex(pulseOutput, outputMode);
    TIM_TypeDef *counter = PlsrCounters[index];
    uint32_t triggerSelection = ((pulseOutput & 2U) == 0U)
                                    ? TIM_SMCR_TS_1
                                    : (TIM_SMCR_TS_1 | TIM_SMCR_TS_0);

    PlsrCounterStop(pulseOutput);
    if ((PlsrCounterOwner[index] != PLSR_COUNTER_NONE)
        && (PlsrCounterOwner[index] != pulseOutput))
    {
        return 0U;
    }
    PlsrCounterOwner[index] = pulseOutput;
    PlsrCounterIndexByOutput[pulseOutput] = index;
    PlsrCounterOverflowPulses[index] = 0UL;
    counter->CR1 = 0UL;
    counter->DIER = 0UL;
    counter->SMCR = 0UL;
    counter->PSC = 0UL;
    counter->ARR = 0xFFFFUL;
    counter->CNT = 0UL;
    counter->EGR = TIM_EGR_UG;
    counter->SR = 0UL;
    /* RM0090 table 101 routes TIM10/11/13/14 OC directly to ITR2/3. */
    counter->SMCR = triggerSelection;
    counter->DIER = TIM_DIER_UIE;
    return 1U;
}

static void PlsrCounterBegin(uint8_t pulseOutput)
{
    uint8_t index = PlsrCounterIndexByOutput[pulseOutput];

    if (index < PLSR_COUNTER_COUNT)
    {
        TIM_TypeDef *counter = PlsrCounters[index];

        counter->SMCR |= TIM_SMCR_SMS_2 | TIM_SMCR_SMS_1 | TIM_SMCR_SMS_0;
        counter->CR1 |= TIM_CR1_CEN;
    }
}

static void PlsrCounterSuspend(uint8_t pulseOutput)
{
    uint8_t index = PlsrCounterIndexByOutput[pulseOutput];

    if (index < PLSR_COUNTER_COUNT)
    {
        PlsrCounters[index]->CR1 &= ~TIM_CR1_CEN;
        PlsrCounters[index]->SMCR &=
            ~(TIM_SMCR_SMS_2 | TIM_SMCR_SMS_1 | TIM_SMCR_SMS_0);
    }
}

static void PlsrAbLoadAndStart(uint8_t pulseOutput,
                               const PLSR_AB_SETTING *setting)
{
    uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
    uint8_t leadOutput =
        (PlsrTimerDirectionPositive[pulseOutput] != 0U)
            ? pulseOutput : pairOutput;
    uint8_t lagOutput = (leadOutput == pulseOutput)
                            ? pairOutput : pulseOutput;
    TIM_TypeDef *baseTimer = PlsrTimerMap[pulseOutput].timer;
    TIM_TypeDef *pairTimer = PlsrTimerMap[pairOutput].timer;
    TIM_TypeDef *counterSourceTimer;
    TIM_TypeDef *otherTimer;
    uint32_t periodCounts = setting->period + 1UL;
    uint32_t leadStart = (periodCounts * 3UL) / 4UL + 1UL;
    uint32_t lagStart = periodCounts / 2UL + 1UL;
    uint32_t counterSourceCr1;
    uint32_t otherCr1;
#if PLSR_DEBUG_TIMING
    uint8_t debugCounterIndex = PlsrCounterIndexByOutput[pulseOutput];
    uint8_t debugReload = PlsrTimerRunning[pulseOutput];

    if ((debugReload != 0U) && (debugCounterIndex < PLSR_COUNTER_COUNT))
    {
        PlsrAbReloadCounterBefore[pulseOutput] =
            (uint16_t)PlsrCounters[debugCounterIndex]->CNT;
        PlsrAbReloadCount[pulseOutput]++;
    }
#endif

    if (leadStart >= periodCounts)
    {
        leadStart = periodCounts - 1UL;
    }
    if (lagStart >= periodCounts)
    {
        lagStart = periodCounts - 1UL;
    }
    PlsrAbStructureVerified[pulseOutput] = 0U;
    PlsrAbLagAxis[pulseOutput] = lagOutput;
    PlsrAbCounterSourceAxis[pulseOutput] =
        (pulseOutput == 0U) ? pulseOutput : pairOutput;
    PlsrAbCounterBoundary[pulseOutput] =
        (PlsrAbCounterSourceAxis[pulseOutput] == leadOutput)
            ? (leadStart - 1UL) : (periodCounts / 2UL);

    PlsrCounterSuspend(pulseOutput);
    baseTimer->CR1 &= ~TIM_CR1_CEN;
    pairTimer->CR1 &= ~TIM_CR1_CEN;
    PlsrAbHoldPairIdle(pulseOutput);
    baseTimer->CCER &= ~TIM_CCER_CC1E;
    pairTimer->CCER &= ~TIM_CCER_CC1E;
    baseTimer->DIER = 0UL;
    pairTimer->DIER = 0UL;
    baseTimer->CCMR1 = TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1PE;
    pairTimer->CCMR1 = TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1PE;
    baseTimer->PSC = setting->basePrescaler;
    pairTimer->PSC = setting->pairPrescaler;
    baseTimer->ARR = setting->period;
    pairTimer->ARR = setting->period;
    baseTimer->CCR1 = setting->compare;
    pairTimer->CCR1 = setting->compare;
    baseTimer->CR1 = TIM_CR1_ARPE | TIM_CR1_URS;
    pairTimer->CR1 = TIM_CR1_ARPE | TIM_CR1_URS;
    baseTimer->EGR = TIM_EGR_UG;
    pairTimer->EGR = TIM_EGR_UG;
    baseTimer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
    pairTimer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
    PlsrTimerMap[leadOutput].timer->CNT = leadStart;
    PlsrTimerMap[lagOutput].timer->CNT = lagStart;
    baseTimer->CCER = (baseTimer->CCER
                       & ~(TIM_CCER_CC1P | TIM_CCER_CC1E))
                      | TIM_CCER_CC1P | TIM_CCER_CC1E;
    pairTimer->CCER = (pairTimer->CCER
                       & ~(TIM_CCER_CC1P | TIM_CCER_CC1E))
                      | TIM_CCER_CC1P | TIM_CCER_CC1E;
    PlsrAbReleasePair(pulseOutput);
    baseTimer->CCMR1 = TIM_CCMR1_OC1PE
                       | (6UL << TIM_CCMR1_OC1M_Pos);
    pairTimer->CCMR1 = TIM_CCMR1_OC1PE
                       | (6UL << TIM_CCMR1_OC1M_Pos);
    PlsrCounterBegin(pulseOutput);
#if PLSR_DEBUG_TIMING
    if ((debugReload != 0U) && (debugCounterIndex < PLSR_COUNTER_COUNT))
    {
        PlsrAbReloadCounterArmed[pulseOutput] =
            (uint16_t)PlsrCounters[debugCounterIndex]->CNT;
    }
#endif
    counterSourceTimer =
        PlsrTimerMap[PlsrAbCounterSourceAxis[pulseOutput]].timer;
    otherTimer =
        PlsrTimerMap[(PlsrAbCounterSourceAxis[pulseOutput] == pulseOutput)
                         ? pairOutput : pulseOutput].timer;
    counterSourceCr1 = counterSourceTimer->CR1 | TIM_CR1_CEN;
    otherCr1 = otherTimer->CR1 | TIM_CR1_CEN;
    PlsrAbEnableTimerPair(counterSourceTimer, counterSourceCr1,
                          otherTimer, otherCr1);
#if PLSR_DEBUG_TIMING
    if ((debugReload != 0U) && (debugCounterIndex < PLSR_COUNTER_COUNT))
    {
        __DSB();
        PlsrAbReloadCounterStarted[pulseOutput] =
            (uint16_t)PlsrCounters[debugCounterIndex]->CNT;
    }
#endif
    baseTimer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
    pairTimer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
    PlsrTimerMap[lagOutput].timer->DIER |= TIM_DIER_CC1IE;
    __DMB();
}

static void PlsrAbScheduleFrequencyVerify(uint8_t pulseOutput)
{
    uint8_t verifyOutput =
        (PlsrAbLagAxis[pulseOutput] == pulseOutput)
            ? (uint8_t)(pulseOutput + 1U) : pulseOutput;
    TIM_TypeDef *verifyTimer = PlsrTimerMap[verifyOutput].timer;

    PlsrFrequencyVerifyPending[pulseOutput] =
        PLSR_FREQUENCY_VERIFY_AB_AUX_IRQ;
    PlsrAbVerifyOwner[verifyOutput] = pulseOutput;
    verifyTimer->SR = ~TIM_SR_UIF;
    verifyTimer->DIER |= TIM_DIER_UIE;
    if (PlsrDeferredPulsePending[pulseOutput] != 0U)
    {
        verifyTimer->SR = ~TIM_SR_CC1IF;
        verifyTimer->DIER |= TIM_DIER_CC1IE;
    }
    __DMB();
}

static uint32_t PlsrFrequencyFromSnapshot(
    uint8_t pulseOutput,
    const PLSR_TIMER_SNAPSHOT *snapshot)
{
    uint64_t divider = ((uint64_t)snapshot->psc + 1UL)
                       * ((uint64_t)snapshot->arr + 1UL);

    if (divider == 0UL)
    {
        return 0UL;
    }
    return (uint32_t)(((uint64_t)PlsrTimerMap[pulseOutput].timerClockHz
                       + divider / 2UL)
                      / divider);
}

static uint32_t PlsrVerifyActiveFrequency(uint8_t pulseOutput)
{
    TIM_TypeDef *baseTimer = PlsrTimerMap[pulseOutput].timer;
    PLSR_TIMER_SNAPSHOT baseSnapshot;
    uint32_t activeFrequency = PlsrTimerActiveFrequencyHz[pulseOutput];

    PlsrTimerSnapshot(baseTimer, &baseSnapshot);

    if (PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
    {
        uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
        TIM_TypeDef *pairTimer = PlsrTimerMap[pairOutput].timer;
        PLSR_TIMER_SNAPSHOT pairSnapshot;
        uint8_t structureValid;

        PlsrTimerSnapshot(pairTimer, &pairSnapshot);
        structureValid = PlsrAbStructureIsRunnable(
            pulseOutput, &baseSnapshot, &pairSnapshot);
        PlsrAbStructureVerified[pulseOutput] = structureValid;

        if (structureValid == 0U)
        {
            PlsrPlatformFaultPending = PLSR_PLATFORM_FAULT_CURVE;
        }
        if ((baseSnapshot.psc
             != PlsrAbActiveSetting[pulseOutput].basePrescaler)
            || (pairSnapshot.psc
                != PlsrAbActiveSetting[pulseOutput].pairPrescaler)
            || (baseSnapshot.arr
                != PlsrAbActiveSetting[pulseOutput].period)
            || (pairSnapshot.arr
                != PlsrAbActiveSetting[pulseOutput].period)
            || (baseSnapshot.ccr1
                != PlsrAbActiveSetting[pulseOutput].compare)
            || (pairSnapshot.ccr1
                != PlsrAbActiveSetting[pulseOutput].compare))
        {
            activeFrequency = PlsrFrequencyFromSnapshot(pairOutput,
                                                        &pairSnapshot);
            if (PlsrPlatformFaultPending != PLSR_PLATFORM_FAULT_CURVE)
            {
                PlsrPlatformFaultPending = PLSR_PLATFORM_FAULT_FREQUENCY;
            }
        }
    }
    else
    {
        uint8_t structureValid =
            ((((baseSnapshot.cr1 & TIM_CR1_CEN) != 0UL)
              && ((baseSnapshot.ccer & TIM_CCER_CC1E) != 0UL)
              && ((baseSnapshot.ccer & TIM_CCER_CC1P) == 0UL)
              && ((baseSnapshot.ccmr1 & PLSR_TIMER_OC1_MODE_MASK)
                  == PLSR_TIMER_PWM1_MODE)
              && (baseSnapshot.ccr1
                  == ((baseSnapshot.arr + 1UL) / 2UL)))
                 ? 1U : 0U);

        if (structureValid == 0U)
        {
            PlsrPlatformFaultPending = PLSR_PLATFORM_FAULT_CURVE;
        }
        if ((baseSnapshot.psc
             != PlsrTimerQueuedSetting[pulseOutput].prescaler)
            || (baseSnapshot.arr
                != PlsrTimerQueuedSetting[pulseOutput].period)
            || (baseSnapshot.ccr1
                != PlsrTimerQueuedSetting[pulseOutput].compare))
        {
            activeFrequency = PlsrFrequencyFromSnapshot(pulseOutput,
                                                        &baseSnapshot);
            if (PlsrPlatformFaultPending != PLSR_PLATFORM_FAULT_CURVE)
            {
                PlsrPlatformFaultPending = PLSR_PLATFORM_FAULT_FREQUENCY;
            }
        }
    }
    if (activeFrequency == 0UL)
    {
        PlsrPlatformFaultPending = PLSR_PLATFORM_FAULT_FREQUENCY;
    }
    return activeFrequency;
}

uint8_t PlsrPlatformInit(void)
{
    GPIO_InitTypeDef gpio;
    uint8_t index;
    const PLSR_BACKUP_POSITION_RECORD *positionRecord;

    PlsrFlashReserveEraseState = PLSR_FLASH_ERASE_NONE;
    __HAL_RCC_GPIOB_CLK_ENABLE();
    __HAL_RCC_GPIOF_CLK_ENABLE();
    __HAL_RCC_GPIOG_CLK_ENABLE();
    __HAL_RCC_GPIOH_CLK_ENABLE();
    __HAL_RCC_TIM10_CLK_ENABLE();
    __HAL_RCC_TIM11_CLK_ENABLE();
    __HAL_RCC_TIM13_CLK_ENABLE();
    __HAL_RCC_TIM14_CLK_ENABLE();
    __HAL_RCC_TIM9_CLK_ENABLE();
    __HAL_RCC_TIM12_CLK_ENABLE();
    __HAL_RCC_PWR_CLK_ENABLE();
    HAL_PWR_EnableBkUpAccess();
    __HAL_RCC_BKPSRAM_CLK_ENABLE();
    if (HAL_PWREx_EnableBkUpReg() != HAL_OK)
    {
        return 0U;
    }

#if PLSR_DEBUG_TIMING
    CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
    DWT->CYCCNT = 0UL;
    DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;
    (void)memset((void *)PlsrIrqCount, 0, sizeof(PlsrIrqCount));
    (void)memset((void *)PlsrIrqLastCycles, 0, sizeof(PlsrIrqLastCycles));
    (void)memset((void *)PlsrIrqMaxCycles, 0, sizeof(PlsrIrqMaxCycles));
    (void)memset((void *)PlsrFinalArmQueueCount, 0,
                 sizeof(PlsrFinalArmQueueCount));
    (void)memset((void *)PlsrFinalArmJobLastCycles, 0,
                 sizeof(PlsrFinalArmJobLastCycles));
    (void)memset((void *)PlsrFinalArmJobMaxCycles, 0,
                 sizeof(PlsrFinalArmJobMaxCycles));
    (void)memset((void *)PlsrFinalArmQueueToStopLastCycles, 0,
                 sizeof(PlsrFinalArmQueueToStopLastCycles));
    (void)memset((void *)PlsrFinalArmQueueToStopMaxCycles, 0,
                 sizeof(PlsrFinalArmQueueToStopMaxCycles));
    (void)memset((void *)PlsrFinalArmQueuedAt, 0,
                 sizeof(PlsrFinalArmQueuedAt));
    (void)memset((void *)PlsrFinalArmQueueTimingPending, 0,
                 sizeof(PlsrFinalArmQueueTimingPending));
#endif

    HAL_GPIO_WritePin(GPIOH, GPIO_PIN_6 | GPIO_PIN_7 | GPIO_PIN_8
                              | GPIO_PIN_9, GPIO_PIN_SET);
    gpio.Pin = GPIO_PIN_6 | GPIO_PIN_7 | GPIO_PIN_8 | GPIO_PIN_9;
    gpio.Mode = GPIO_MODE_OUTPUT_PP;
    gpio.Pull = GPIO_NOPULL;
    gpio.Speed = GPIO_SPEED_FREQ_HIGH;
    gpio.Alternate = 0U;
    HAL_GPIO_Init(GPIOH, &gpio);

    gpio.Mode = GPIO_MODE_INPUT;
    gpio.Pull = GPIO_NOPULL;
    gpio.Speed = GPIO_SPEED_FREQ_LOW;
    gpio.Alternate = 0U;
    gpio.Pin = GPIO_PIN_5;
    HAL_GPIO_Init(GPIOB, &gpio);
    gpio.Pin = GPIO_PIN_12;
    HAL_GPIO_Init(GPIOG, &gpio);

    for (index = 0U; index < 4U; index++)
    {
        PlsrTimerActiveFrequencyHz[index] = 0UL;
        PlsrTimerQueuedFrequencyHz[index] = 0UL;
        (void)memset(&PlsrTimerActiveSetting[index], 0,
                     sizeof(PlsrTimerActiveSetting[index]));
        (void)memset(&PlsrTimerQueuedSetting[index], 0,
                     sizeof(PlsrTimerQueuedSetting[index]));
        PlsrTimerQueueGeneration[index] = 0UL;
        PlsrTimerOutputMode[index] = PLSR_OUTPUT_PULSE_DIR;
        PlsrTimerDirectionPositive[index] = 1U;
        PlsrTimerRunning[index] = 0U;
        PlsrFrequencyVerifyPending[index] = 0U;
        PlsrFrequencyVerifyPulseCount[index] = 0U;
        PlsrDeferredPulsePending[index] = 0U;
        PlsrAbVerifyOwner[index] = PLSR_COUNTER_NONE;
        PlsrAbFinalArmJobOwner[index] = PLSR_COUNTER_NONE;
        PlsrTimerIrqActive[index] = 0U;
        PlsrAbFrequencyPending[index] = 0U;
        PlsrAbLagAxis[index] = PLSR_COUNTER_NONE;
        PlsrAbStructureVerified[index] = 0U;
        PlsrAbCounterSourceAxis[index] = PLSR_COUNTER_NONE;
        PlsrAbCounterBoundary[index] = 0UL;
        PlsrAbStopPending[index] = 0U;
        PlsrAbFastGated[index] = 0U;
        PlsrCounterIndexByOutput[index] = PLSR_COUNTER_NONE;
        PlsrObservedPulseBase[index] = 0UL;
        PlsrObservedPulsePublished[index] = 0UL;
        PlsrFiniteActive[index] = 0U;
        PlsrFiniteCompletionPending[index] = 0U;
        PlsrFiniteFrequencyPending[index] = 0U;
        PlsrFiniteRetargetPending[index] = 0U;
        PlsrFiniteTailStopPending[index] = 0U;
        PlsrFiniteRetargetDrainPulses[index] = 0UL;
        PlsrFiniteTargetPulses[index] = 0UL;
        PlsrFiniteRemainingPulses[index] = 0UL;
        PlsrFiniteCounterPreload[index] = 0U;
        PlsrFiniteStepCount[index] = 0U;
        PlsrFiniteStepIndex[index] = 0U;
        PlsrFiniteBoundaryReadIndex[index] = 0U;
        PlsrFiniteCompletedStepCount[index] = 0U;
        PlsrTimerInitialize(PlsrTimerMap[index].timer);
        PlsrPulsePinHoldIdle(index);
        HAL_NVIC_SetPriority(PlsrTimerMap[index].irq, 0U, 0U);
        HAL_NVIC_EnableIRQ(PlsrTimerMap[index].irq);
    }
    for (index = 0U; index < PLSR_COUNTER_COUNT; index++)
    {
        PlsrCounterOwner[index] = PLSR_COUNTER_NONE;
        PlsrCounterOverflowPulses[index] = 0UL;
        PlsrCounters[index]->CR1 = 0UL;
        PlsrCounters[index]->DIER = 0UL;
        PlsrCounters[index]->SMCR = 0UL;
        PlsrCounters[index]->SR = 0UL;
    }
    PlsrPlatformFaultPending = 0U;
    HAL_NVIC_SetPriority(TIM1_BRK_TIM9_IRQn, 0U, 0U);
    HAL_NVIC_EnableIRQ(TIM1_BRK_TIM9_IRQn);
    HAL_NVIC_SetPriority(TIM8_BRK_TIM12_IRQn, 0U, 0U);
    HAL_NVIC_EnableIRQ(TIM8_BRK_TIM12_IRQn);

    positionRecord = PlsrNewestBackupPosition();
    PlsrBackupPositionGeneration =
        (positionRecord == NULL) ? 0UL : positionRecord->generation;
    return 1U;
}

uint8_t PlsrPlatformPrepare(uint8_t pulseOutput,
                            uint8_t directionOutput,
                            uint8_t directionLevel,
                            uint8_t outputMode,
                            uint8_t directionPositive)
{
    uint8_t index;

    if ((pulseOutput > 3U) || (directionOutput > 3U)
        || (outputMode > PLSR_OUTPUT_AB)
        || ((outputMode == PLSR_OUTPUT_AB)
            && (pulseOutput != 0U) && (pulseOutput != 2U)))
    {
        return 0U;
    }
    if ((PlsrAbStopPending[0] != 0U) || (PlsrAbStopPending[2] != 0U))
    {
        return 0U;
    }
    for (index = 0U; index < 4U; index++)
    {
        PlsrAbFinalArmJobOwner[index] = PLSR_COUNTER_NONE;
        NVIC_ClearPendingIRQ(PlsrTimerMap[index].irq);
        PlsrCounterStop(index);
        PlsrPulsePinHoldIdle(index);
        PlsrTimerStop(PlsrTimerMap[index].timer);
        HAL_GPIO_WritePin(PlsrDirectionMap[index].port,
                          PlsrDirectionMap[index].pin,
                          ((outputMode == PLSR_OUTPUT_PULSE_DIR)
                           && (index == directionOutput)
                           && (directionLevel != 0U))
                              ? GPIO_PIN_RESET : GPIO_PIN_SET);
        PlsrTimerRunning[index] = 0U;
        PlsrFrequencyVerifyPending[index] = 0U;
        PlsrFrequencyVerifyPulseCount[index] = 0U;
        PlsrDeferredPulsePending[index] = 0U;
        PlsrAbVerifyOwner[index] = PLSR_COUNTER_NONE;
        PlsrAbFrequencyPending[index] = 0U;
        PlsrAbStructureVerified[index] = 0U;
        PlsrAbFastGated[index] = 0U;
    }
    PlsrTimerOutputMode[pulseOutput] = outputMode;
    PlsrTimerDirectionPositive[pulseOutput] =
        (directionPositive != 0U) ? 1U : 0U;
    PlsrPlatformFaultPending = 0U;
    return 1U;
}

uint8_t PlsrPlatformStartPulse(uint8_t pulseOutput,
                               uint32_t firstFrequencyHz,
                               uint32_t queuedFrequencyHz,
                               uint32_t *actualFirstFrequencyHz,
                               uint32_t *actualQueuedFrequencyHz)
{
    PLSR_PLATFORM_TIMER_SETTING firstSetting;
    PLSR_PLATFORM_TIMER_SETTING queuedSetting;

    if ((pulseOutput > 3U)
        || (PlsrPlatformBuildTimerSetting(
                pulseOutput, PlsrTimerOutputMode[pulseOutput],
                firstFrequencyHz, &firstSetting) == 0U)
        || (PlsrPlatformBuildTimerSetting(
                pulseOutput, PlsrTimerOutputMode[pulseOutput],
                queuedFrequencyHz, &queuedSetting) == 0U))
    {
        return 0U;
    }
    return PlsrPlatformStartPrepared(pulseOutput, &firstSetting,
                                     &queuedSetting,
                                     actualFirstFrequencyHz,
                                     actualQueuedFrequencyHz);
}

static uint8_t PlsrPreparedSettingIsValid(
    uint8_t pulseOutput,
    uint8_t outputMode,
    const PLSR_PLATFORM_TIMER_SETTING *setting)
{
    uint32_t periodCounts;

    if ((pulseOutput > 3U) || (setting == NULL)
        || (setting->actualFrequencyHz == 0UL)
        || (setting->actualFrequencyHz > PLSR_FREQUENCY_MAX_HZ))
    {
        return 0U;
    }
    periodCounts = (uint32_t)setting->period + 1UL;
    if (setting->compare != (uint16_t)(periodCounts / 2UL))
    {
        return 0U;
    }
    if (outputMode == PLSR_OUTPUT_PULSE_DIR)
    {
        return ((periodCounts >= 2UL)
                && (setting->pairPrescaler == 0U)) ? 1U : 0U;
    }
    if ((outputMode != PLSR_OUTPUT_AB) || ((pulseOutput & 1U) != 0U)
        || (periodCounts < 4UL))
    {
        return 0U;
    }
    return ((((uint32_t)setting->prescaler + 1UL)
             == 2UL * ((uint32_t)setting->pairPrescaler + 1UL))
                ? 1U : 0U);
}

static void PlsrPlatformToTimerSetting(
    const PLSR_PLATFORM_TIMER_SETTING *source,
    PLSR_TIMER_SETTING *destination)
{
    destination->prescaler = source->prescaler;
    destination->period = source->period;
    destination->compare = source->compare;
    destination->actualFrequencyHz = source->actualFrequencyHz;
}

static void PlsrPlatformToAbSetting(
    const PLSR_PLATFORM_TIMER_SETTING *source,
    PLSR_AB_SETTING *destination)
{
    destination->basePrescaler = source->prescaler;
    destination->pairPrescaler = source->pairPrescaler;
    destination->period = source->period;
    destination->compare = source->compare;
    destination->actualFrequencyHz = source->actualFrequencyHz;
}

static uint8_t PlsrPlatformSettingsDiffer(
    const PLSR_PLATFORM_TIMER_SETTING *first,
    const PLSR_PLATFORM_TIMER_SETTING *second)
{
    return (((first->actualFrequencyHz != second->actualFrequencyHz)
             || (first->prescaler != second->prescaler)
             || (first->pairPrescaler != second->pairPrescaler)
             || (first->period != second->period)
             || (first->compare != second->compare)) ? 1U : 0U);
}

uint8_t PlsrPlatformBuildTimerSetting(
    uint8_t pulseOutput,
    uint8_t outputMode,
    uint32_t requestedFrequencyHz,
    PLSR_PLATFORM_TIMER_SETTING *setting)
{
    PLSR_TIMER_SETTING timerSetting;
    PLSR_AB_SETTING abSetting;

    if (setting == NULL)
    {
        return 0U;
    }
    if (outputMode == PLSR_OUTPUT_AB)
    {
        if (PlsrAbCalculate(pulseOutput, requestedFrequencyHz,
                            &abSetting) == 0U)
        {
            return 0U;
        }
        setting->actualFrequencyHz = abSetting.actualFrequencyHz;
        setting->prescaler = (uint16_t)abSetting.basePrescaler;
        setting->pairPrescaler = (uint16_t)abSetting.pairPrescaler;
        setting->period = (uint16_t)abSetting.period;
        setting->compare = (uint16_t)abSetting.compare;
        return 1U;
    }
    if ((outputMode != PLSR_OUTPUT_PULSE_DIR)
        || (PlsrTimerCalculate(pulseOutput, requestedFrequencyHz,
                               &timerSetting) == 0U))
    {
        return 0U;
    }
    setting->actualFrequencyHz = timerSetting.actualFrequencyHz;
    setting->prescaler = (uint16_t)timerSetting.prescaler;
    setting->pairPrescaler = 0U;
    setting->period = (uint16_t)timerSetting.period;
    setting->compare = (uint16_t)timerSetting.compare;
    return 1U;
}

uint8_t PlsrPlatformStartPrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *firstSetting,
    const PLSR_PLATFORM_TIMER_SETTING *queuedSetting,
    uint32_t *actualFirstFrequencyHz,
    uint32_t *actualQueuedFrequencyHz)
{
    uint8_t outputMode;

    if ((pulseOutput > 3U) || (actualFirstFrequencyHz == NULL)
        || (actualQueuedFrequencyHz == NULL))
    {
        return 0U;
    }
    outputMode = PlsrTimerOutputMode[pulseOutput];
    if ((PlsrPreparedSettingIsValid(pulseOutput, outputMode,
                                    firstSetting) == 0U)
        || (PlsrPreparedSettingIsValid(pulseOutput, outputMode,
                                       queuedSetting) == 0U))
    {
        return 0U;
    }
    if (outputMode == PLSR_OUTPUT_AB)
    {
        PLSR_AB_SETTING firstAbSetting;
        PLSR_AB_SETTING queuedAbSetting;

        if ((PlsrAbStopPending[pulseOutput] != 0U)
            || (PlsrAbFastGated[pulseOutput] != 0U)
            || (PlsrCounterConfigure(pulseOutput, PLSR_OUTPUT_AB) == 0U))
        {
            return 0U;
        }
        PlsrPlatformToAbSetting(firstSetting, &firstAbSetting);
        PlsrPlatformToAbSetting(queuedSetting, &queuedAbSetting);
        PlsrAbLoadAndStart(pulseOutput, &firstAbSetting);
        PlsrAbActiveSetting[pulseOutput] = firstAbSetting;
        PlsrAbPendingSetting[pulseOutput] = queuedAbSetting;
        PlsrAbFrequencyPending[pulseOutput] =
            ((firstSetting->prescaler != queuedSetting->prescaler)
             || (firstSetting->pairPrescaler
                 != queuedSetting->pairPrescaler)
             || (firstSetting->period != queuedSetting->period)) ? 1U : 0U;
    }
    else
    {
        TIM_TypeDef *timer = PlsrTimerMap[pulseOutput].timer;
        PLSR_TIMER_SETTING firstTimerSetting;
        PLSR_TIMER_SETTING queuedTimerSetting;

        if (PlsrCounterConfigure(pulseOutput,
                                 PLSR_OUTPUT_PULSE_DIR) == 0U)
        {
            return 0U;
        }
        PlsrPlatformToTimerSetting(firstSetting, &firstTimerSetting);
        PlsrPlatformToTimerSetting(queuedSetting, &queuedTimerSetting);
        timer->DIER &= ~TIM_DIER_UIE;
        timer->CR1 &= ~TIM_CR1_CEN;
        timer->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
        timer->CNT = 0UL;
        PlsrTimerWriteSetting(timer, &firstTimerSetting);
        timer->EGR = TIM_EGR_UG;
        PlsrTimerWriteSetting(timer, &queuedTimerSetting);
        timer->CNT = firstTimerSetting.compare;
        timer->SR = 0UL;
        timer->CCER = (timer->CCER
                       & ~(TIM_CCER_CC1E | TIM_CCER_CC1P))
                      | TIM_CCER_CC1E;
        __DSB();
        timer->DIER |= TIM_DIER_UIE;
        PlsrPulsePinRelease(pulseOutput);
        PlsrCounterBegin(pulseOutput);
        timer->CR1 |= TIM_CR1_CEN;
    }
    PlsrTimerActiveSetting[pulseOutput] = *firstSetting;
    PlsrTimerQueuedSetting[pulseOutput] = *queuedSetting;
    PlsrTimerActiveFrequencyHz[pulseOutput] =
        firstSetting->actualFrequencyHz;
    PlsrTimerQueuedFrequencyHz[pulseOutput] =
        queuedSetting->actualFrequencyHz;
    PlsrTimerQueueGeneration[pulseOutput]++;
    PlsrTimerRunning[pulseOutput] = 1U;
    if (outputMode == PLSR_OUTPUT_AB)
    {
        PlsrAbScheduleFrequencyVerify(pulseOutput);
    }
    else
    {
        PlsrFrequencyVerifyPending[pulseOutput] =
            PLSR_FREQUENCY_VERIFY_NOW;
    }
    PlsrFrequencyVerifyPulseCount[pulseOutput] = 0U;
    *actualFirstFrequencyHz = firstSetting->actualFrequencyHz;
    *actualQueuedFrequencyHz = queuedSetting->actualFrequencyHz;
    return 1U;
}

uint8_t PlsrPlatformSupportsFinitePulseTrain(void)
{
    return 1U;
}

uint8_t PlsrPlatformStartFinitePrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t pulseCount,
    uint32_t *actualFrequencyHz)
{
    TIM_TypeDef *timer;
    TIM_TypeDef *counter;
    PLSR_TIMER_SETTING timerSetting;
    uint32_t firstBlock;
    uint8_t counterIndex;

    if ((pulseOutput > 3U) || (setting == NULL)
        || (pulseCount == 0UL) || (actualFrequencyHz == NULL)
        || (PlsrTimerOutputMode[pulseOutput] != PLSR_OUTPUT_PULSE_DIR)
        || (PlsrPreparedSettingIsValid(pulseOutput,
                                       PLSR_OUTPUT_PULSE_DIR,
                                       setting) == 0U)
        || (PlsrCounterConfigure(pulseOutput,
                                 PLSR_OUTPUT_PULSE_DIR) == 0U))
    {
        return 0U;
    }

    timer = PlsrTimerMap[pulseOutput].timer;
    counterIndex = PlsrCounterIndexByOutput[pulseOutput];
    counter = PlsrCounters[counterIndex];
    firstBlock = (pulseCount > PLSR_COUNTER_BLOCK_PULSES)
                     ? PLSR_COUNTER_BLOCK_PULSES : pulseCount;
    PlsrPlatformToTimerSetting(setting, &timerSetting);

    counter->CR1 &= ~TIM_CR1_CEN;
    counter->SMCR &= ~(TIM_SMCR_SMS_2 | TIM_SMCR_SMS_1 | TIM_SMCR_SMS_0);
    counter->ARR = (firstBlock == 1UL) ? 1UL : (firstBlock - 1UL);
    counter->CNT = 0UL;
    counter->EGR = TIM_EGR_UG;
    PlsrFiniteCounterPreload[pulseOutput] =
        (firstBlock == 1UL) ? 1U : 0U;
    counter->CNT = PlsrFiniteCounterPreload[pulseOutput];
    counter->SR = 0UL;
    counter->DIER = TIM_DIER_UIE;

    timer->DIER = 0UL;
    timer->CR1 &= ~TIM_CR1_CEN;
    timer->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
    timer->CNT = 0UL;
    PlsrTimerWriteSetting(timer, &timerSetting);
    timer->EGR = TIM_EGR_UG;
    /*
     * The board's high-speed output stage is active low.  Keep OC1 high
     * while the pin changes from GPIO idle to the timer alternate function,
     * then let the first terminal pulse start at CCR1.  Starting at CCR1
     * would expose an uncounted terminal pulse before the first OC rising
     * edge reaches TIM9/TIM12.
     */
    timer->CNT = 0UL;
    timer->SR = 0UL;
    timer->CCER = (timer->CCER
                   & ~(TIM_CCER_CC1E | TIM_CCER_CC1P))
                  | TIM_CCER_CC1E;
    PlsrFiniteTargetPulses[pulseOutput] = pulseCount;
    PlsrFiniteRemainingPulses[pulseOutput] = pulseCount;
    PlsrFiniteCompletionPending[pulseOutput] = 0U;
    PlsrFiniteFrequencyPending[pulseOutput] = 0U;
    PlsrFiniteStreamActive[pulseOutput] = 0U;
    PlsrFiniteStreamNextValid[pulseOutput] = 0U;
    PlsrFiniteStreamSourceDone[pulseOutput] = 0U;
    PlsrFiniteStreamSourceFault[pulseOutput] = 0U;
    PlsrFiniteActive[pulseOutput] = 1U;
    PlsrFiniteStepCount[pulseOutput] = 0U;
    PlsrFiniteStepIndex[pulseOutput] = 0U;
    PlsrFiniteBoundaryReadIndex[pulseOutput] = 0U;
    PlsrFiniteCompletedStepCount[pulseOutput] = 0U;
    PlsrTimerActiveSetting[pulseOutput] = *setting;
    PlsrTimerQueuedSetting[pulseOutput] = *setting;
    PlsrTimerActiveFrequencyHz[pulseOutput] = setting->actualFrequencyHz;
    PlsrTimerQueuedFrequencyHz[pulseOutput] = setting->actualFrequencyHz;
    PlsrTimerRunning[pulseOutput] = 1U;
    *actualFrequencyHz = setting->actualFrequencyHz;

    __DSB();
    PlsrPulsePinRelease(pulseOutput);
    PlsrCounterBegin(pulseOutput);
    timer->CR1 |= TIM_CR1_CEN;
    return 1U;
}

uint8_t PlsrPlatformStartCountedStreamPrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t pulseCount,
    uint32_t *actualFrequencyHz)
{
    TIM_TypeDef *counter;
    uint32_t firstBlock;

    if (PlsrPlatformStartFinitePrepared(pulseOutput, setting, pulseCount,
                                        actualFrequencyHz) == 0U)
    {
        return 0U;
    }
    PlsrFiniteStreamActive[pulseOutput] = 1U;
    PlsrFiniteStreamNextValid[pulseOutput] = 0U;
    PlsrFiniteStreamNextStartsSegment[pulseOutput] = 0U;
    PlsrFiniteStreamSourceDone[pulseOutput] = 0U;
    PlsrFiniteStreamSourceFault[pulseOutput] = 0U;
    firstBlock = (pulseCount > PLSR_COUNTER_BLOCK_PULSES)
                     ? PLSR_COUNTER_BLOCK_PULSES : pulseCount;
    counter = PlsrCounters[PlsrCounterIndexByOutput[pulseOutput]];
    PlsrFiniteArmNextStepPrepare(pulseOutput, counter, firstBlock);
    return 1U;
}

uint8_t PlsrPlatformStartFiniteSequencePrepared(
    uint8_t pulseOutput,
    PLSR_PLATFORM_FINITE_STEP *steps,
    uint16_t stepCount,
    uint32_t *actualFrequencyHz)
{
    TIM_TypeDef *counter;
    uint16_t index;

    if ((steps == NULL) || (stepCount == 0U)
        || (stepCount > PLSR_PLATFORM_FINITE_STEP_MAX))
    {
        return 0U;
    }
    for (index = 0U; index < stepCount; index++)
    {
        if ((steps[index].pulseCount == 0UL)
            || (steps[index].segmentNumber == 0U)
            || (PlsrPreparedSettingIsValid(
                    pulseOutput, PLSR_OUTPUT_PULSE_DIR,
                    &steps[index].setting) == 0U))
        {
            return 0U;
        }
    }
    if (PlsrPlatformStartFinitePrepared(
            pulseOutput, &steps[0].setting, steps[0].pulseCount,
            actualFrequencyHz) == 0U)
    {
        return 0U;
    }
    PlsrFiniteSteps[pulseOutput] = steps;
    PlsrFiniteStepCount[pulseOutput] = stepCount;
    PlsrFiniteStepIndex[pulseOutput] = 0U;
    PlsrFiniteBoundaryReadIndex[pulseOutput] = 0U;
    PlsrFiniteCompletedStepCount[pulseOutput] = 0U;
    if (stepCount > 1U)
    {
        counter = PlsrCounters[PlsrCounterIndexByOutput[pulseOutput]];
        PlsrFiniteArmNextStepPrepare(
            pulseOutput, counter,
            (steps[0].pulseCount > PLSR_COUNTER_BLOCK_PULSES)
                ? PLSR_COUNTER_BLOCK_PULSES : steps[0].pulseCount);
    }
    return 1U;
}

PLSR_PLATFORM_QUEUE_RESULT PlsrPlatformUpdateFinitePrepared(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t *actualFrequencyHz)
{
    TIM_TypeDef *timer;
    uint32_t activePeriod;
    uint32_t counter;
    uint32_t criticalState;

    if ((pulseOutput > 3U) || (setting == NULL)
        || (actualFrequencyHz == NULL)
        || (PlsrFiniteActive[pulseOutput] == 0U)
        || (PlsrPreparedSettingIsValid(pulseOutput,
                                       PLSR_OUTPUT_PULSE_DIR,
                                       setting) == 0U))
    {
        return PLSR_PLATFORM_QUEUE_STALE;
    }

    timer = PlsrTimerMap[pulseOutput].timer;
    criticalState = PlsrPlatformEnterCritical();
    if ((PlsrFiniteActive[pulseOutput] == 0U)
        || ((timer->CR1 & TIM_CR1_CEN) == 0UL))
    {
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    if (PlsrFiniteFrequencyPending[pulseOutput] != 0U)
    {
        if ((timer->SR & TIM_SR_UIF) == 0UL)
        {
            PlsrPlatformExitCritical(criticalState);
            return PLSR_PLATFORM_QUEUE_STALE;
        }

        /* The update IRQ normally commits this preload.  Also consume a
           latched update here so a delayed/shared IRQ cannot stall a ramp. */
        timer->SR = ~TIM_SR_UIF;
        timer->DIER &= ~TIM_DIER_UIE;
        PlsrTimerActiveFrequencyHz[pulseOutput] =
            PlsrTimerQueuedFrequencyHz[pulseOutput];
        PlsrTimerActiveSetting[pulseOutput] =
            PlsrTimerQueuedSetting[pulseOutput];
        PlsrFiniteFrequencyPending[pulseOutput] = 0U;
    }
    activePeriod = PlsrTimerActiveSetting[pulseOutput].period;
    counter = timer->CNT;
    if ((counter > activePeriod)
        || ((activePeriod - counter) < PLSR_FINITE_WRITE_GUARD_COUNTS))
    {
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_STALE;
    }

    timer->PSC = setting->prescaler;
    timer->ARR = setting->period;
    timer->CCR1 = setting->compare;
    __DMB();
    PlsrTimerQueuedSetting[pulseOutput] = *setting;
    PlsrTimerQueuedFrequencyHz[pulseOutput] = setting->actualFrequencyHz;
    PlsrTimerQueueGeneration[pulseOutput]++;
    PlsrFiniteFrequencyPending[pulseOutput] = 1U;
    timer->SR = ~TIM_SR_UIF;
    timer->DIER |= TIM_DIER_UIE;
    *actualFrequencyHz = setting->actualFrequencyHz;
    PlsrPlatformExitCritical(criticalState);
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

uint8_t PlsrPlatformRetargetFiniteStop(uint8_t pulseOutput,
                                       uint32_t drainPulses)
{
    TIM_TypeDef *timer;

    if ((pulseOutput > 3U) || (drainPulses == 0UL)
        || (PlsrFiniteActive[pulseOutput] == 0U)
        || (PlsrCounterIndexByOutput[pulseOutput] >= PLSR_COUNTER_COUNT)
        || (PlsrFiniteRetargetPending[pulseOutput] != 0U)
        || (PlsrFiniteTailStopPending[pulseOutput] != 0U))
    {
        return 0U;
    }
    timer = PlsrTimerMap[pulseOutput].timer;
    PlsrFiniteRetargetDrainPulses[pulseOutput] = drainPulses;
    PlsrFiniteRetargetPending[pulseOutput] = 1U;
    timer->SR = ~TIM_SR_CC1IF;
    timer->DIER |= TIM_DIER_CC1IE;
    __DMB();
    return 1U;
}

uint8_t PlsrPlatformFiniteRetargetReady(uint8_t pulseOutput,
                                        uint32_t *activeFrequencyHz)
{
    uint32_t criticalState;
    uint8_t ready;

    if ((pulseOutput > 3U) || (activeFrequencyHz == NULL))
    {
        return 0U;
    }
    criticalState = PlsrPlatformEnterCritical();
    ready = ((PlsrFiniteActive[pulseOutput] != 0U)
             && (PlsrFiniteRetargetPending[pulseOutput] == 0U)
             && (PlsrFiniteStepCount[pulseOutput] == 0U)) ? 1U : 0U;
    *activeFrequencyHz = PlsrTimerActiveFrequencyHz[pulseOutput];
    PlsrPlatformExitCritical(criticalState);
    return ready;
}

uint8_t PlsrPlatformFinitePipelineSnapshot(uint8_t pulseOutput,
                                           uint32_t *committedPulses,
                                           uint32_t *tailFrequencyHz,
                                           uint8_t *startsNextSegment)
{
    TIM_TypeDef *counter;
    uint32_t criticalState;
    uint32_t blockCount;
    uint32_t remaining;

    if ((pulseOutput > 3U) || (committedPulses == NULL)
        || (tailFrequencyHz == NULL) || (startsNextSegment == NULL))
    {
        return 0U;
    }
    criticalState = PlsrPlatformEnterCritical();
    if ((PlsrFiniteActive[pulseOutput] == 0U)
        || (PlsrFiniteStreamActive[pulseOutput] == 0U)
        || (PlsrCounterIndexByOutput[pulseOutput] >= PLSR_COUNTER_COUNT))
    {
        PlsrPlatformExitCritical(criticalState);
        return 0U;
    }
    counter = PlsrCounters[PlsrCounterIndexByOutput[pulseOutput]];
    blockCount = (uint16_t)counter->CNT;
    if (blockCount >= PlsrFiniteCounterPreload[pulseOutput])
    {
        blockCount -= PlsrFiniteCounterPreload[pulseOutput];
    }
    else
    {
        blockCount = 0UL;
    }
    remaining = PlsrFiniteRemainingPulses[pulseOutput];
    if (blockCount > remaining)
    {
        blockCount = remaining;
    }
    remaining -= blockCount;
    *tailFrequencyHz = PlsrTimerActiveFrequencyHz[pulseOutput];
    *startsNextSegment = 0U;
    if (PlsrFiniteStreamNextValid[pulseOutput] != 0U)
    {
        uint32_t nextPulses = PlsrFiniteStreamNextPulses[pulseOutput];

        remaining = (nextPulses > (0xFFFFFFFFUL - remaining))
                        ? 0xFFFFFFFFUL : remaining + nextPulses;
        *tailFrequencyHz =
            PlsrFiniteStreamNextSetting[pulseOutput].actualFrequencyHz;
        *startsNextSegment =
            PlsrFiniteStreamNextStartsSegment[pulseOutput];
    }
    *committedPulses = remaining;
    PlsrPlatformExitCritical(criticalState);
    return 1U;
}

uint8_t PlsrPlatformFiniteProgress(uint8_t pulseOutput,
                                   uint32_t *completedPulses)
{
    uint8_t counterIndex;
    TIM_TypeDef *counter;
    uint32_t criticalState;
    uint32_t completed;

    if ((pulseOutput > 3U) || (completedPulses == NULL)
        || ((PlsrFiniteActive[pulseOutput] == 0U)
            && (PlsrFiniteCompletionPending[pulseOutput] == 0U)))
    {
        return 0U;
    }

    criticalState = PlsrPlatformEnterCritical();
    counterIndex = PlsrCounterIndexByOutput[pulseOutput];
    if (PlsrFiniteCompletionPending[pulseOutput] != 0U)
    {
        completed = PlsrFiniteTargetPulses[pulseOutput];
    }
    else if (counterIndex < PLSR_COUNTER_COUNT)
    {
        counter = PlsrCounters[counterIndex];
        uint32_t blockCount = (uint16_t)counter->CNT;

        if (blockCount >= PlsrFiniteCounterPreload[pulseOutput])
        {
            blockCount -= PlsrFiniteCounterPreload[pulseOutput];
        }
        completed = PlsrFiniteTargetPulses[pulseOutput]
                    - PlsrFiniteRemainingPulses[pulseOutput]
                    + blockCount;
        if (completed > PlsrFiniteTargetPulses[pulseOutput])
        {
            completed = PlsrFiniteTargetPulses[pulseOutput];
        }
    }
    else
    {
        PlsrPlatformExitCritical(criticalState);
        return 0U;
    }
    if (PlsrFiniteStepCount[pulseOutput] != 0U)
    {
        completed += PlsrFiniteSteps[pulseOutput][
            PlsrFiniteStepIndex[pulseOutput]].segmentPulseOffset;
    }
    *completedPulses = completed;
    PlsrPlatformExitCritical(criticalState);
    return 1U;
}

uint8_t PlsrPlatformTakeFiniteCompletion(uint8_t pulseOutput,
                                         uint32_t *completedPulses)
{
    uint8_t counterIndex;
    TIM_TypeDef *counter;

    if ((pulseOutput > 3U) || (completedPulses == NULL)
        || (PlsrFiniteCompletionPending[pulseOutput] == 0U))
    {
        return 0U;
    }

    counterIndex = PlsrCounterIndexByOutput[pulseOutput];
    if (PlsrFiniteStepCount[pulseOutput] != 0U)
    {
        const PLSR_PLATFORM_FINITE_STEP *step =
            &PlsrFiniteSteps[pulseOutput][
                PlsrFiniteStepCount[pulseOutput] - 1U];

        *completedPulses = step->segmentPulseOffset + step->pulseCount;
    }
    else
    {
        *completedPulses = PlsrFiniteTargetPulses[pulseOutput];
    }
    if ((PlsrFiniteStepCount[pulseOutput] == 0U)
        && (PlsrFiniteStreamActive[pulseOutput] == 0U))
    {
        PlsrObservedPulseBase[pulseOutput] += *completedPulses;
    }
    PlsrObservedPulsePublished[pulseOutput] =
        PlsrObservedPulseBase[pulseOutput];
    PlsrFiniteCompletionPending[pulseOutput] = 0U;
    PlsrFiniteFrequencyPending[pulseOutput] = 0U;
    PlsrFiniteTargetPulses[pulseOutput] = 0UL;
    PlsrFiniteRemainingPulses[pulseOutput] = 0UL;
    PlsrFiniteCounterPreload[pulseOutput] = 0U;
    PlsrFiniteStepCount[pulseOutput] = 0U;
    PlsrFiniteStepIndex[pulseOutput] = 0U;
    PlsrFiniteStreamActive[pulseOutput] = 0U;
    PlsrFiniteStreamNextValid[pulseOutput] = 0U;
    PlsrFiniteStreamNextStartsSegment[pulseOutput] = 0U;
    PlsrFiniteStreamSourceDone[pulseOutput] = 0U;
    PlsrFiniteStreamSourceFault[pulseOutput] = 0U;
    PlsrTimerActiveFrequencyHz[pulseOutput] = 0UL;
    PlsrTimerQueuedFrequencyHz[pulseOutput] = 0UL;
    PlsrTimerRunning[pulseOutput] = 0U;

    if (counterIndex < PLSR_COUNTER_COUNT)
    {
        counter = PlsrCounters[counterIndex];
        counter->CR1 = 0UL;
        counter->DIER = 0UL;
        counter->SMCR = 0UL;
        counter->SR = 0UL;
        PlsrCounterOverflowPulses[counterIndex] = 0UL;
        PlsrCounterOwner[counterIndex] = PLSR_COUNTER_NONE;
    }
    PlsrCounterIndexByOutput[pulseOutput] = PLSR_COUNTER_NONE;
    return 1U;
}

uint8_t PlsrPlatformTakeFiniteBoundary(uint8_t pulseOutput,
                                       uint8_t *segmentNumber,
                                       uint32_t *completedPulses,
                                       uint8_t *sequenceContinues,
                                       uint32_t *activeFrequencyHz)
{
    uint32_t criticalState;
    uint16_t readIndex;
    uint16_t completedCount;

    if ((pulseOutput > 3U) || (segmentNumber == NULL)
        || (completedPulses == NULL) || (sequenceContinues == NULL)
        || (activeFrequencyHz == NULL))
    {
        return 0U;
    }
    criticalState = PlsrPlatformEnterCritical();
    readIndex = PlsrFiniteBoundaryReadIndex[pulseOutput];
    completedCount = PlsrFiniteCompletedStepCount[pulseOutput];
    while (readIndex < completedCount)
    {
        uint16_t index = readIndex++;
        const PLSR_PLATFORM_FINITE_STEP *step =
            &PlsrFiniteSteps[pulseOutput][index];

        PlsrFiniteBoundaryReadIndex[pulseOutput] = readIndex;
        if (step->completesSegment != 0U)
        {
            *segmentNumber = step->segmentNumber;
            *completedPulses = step->segmentPulseOffset + step->pulseCount;
            *sequenceContinues =
                (index + 1U < PlsrFiniteStepCount[pulseOutput]) ? 1U : 0U;
            *activeFrequencyHz = (*sequenceContinues != 0U)
                ? PlsrFiniteSteps[pulseOutput][index + 1U]
                      .setting.actualFrequencyHz
                : step->setting.actualFrequencyHz;
            PlsrPlatformExitCritical(criticalState);
            return 1U;
        }
    }
    PlsrPlatformExitCritical(criticalState);
    return 0U;
}

PLSR_PLATFORM_QUEUE_RESULT PlsrPlatformLoadPreparedFromIrq(
    uint8_t pulseOutput,
    const PLSR_PLATFORM_TIMER_SETTING *setting,
    uint32_t *actualFrequencyHz)
{
    uint8_t outputMode;

    if ((pulseOutput > 3U) || (actualFrequencyHz == NULL))
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    outputMode = PlsrTimerOutputMode[pulseOutput];
    if (PlsrPreparedSettingIsValid(pulseOutput, outputMode,
                                   setting) == 0U)
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if ((PlsrTimerRunning[pulseOutput] == 0U)
        || (PlsrAbStopPending[pulseOutput] != 0U)
        || (PlsrAbFastGated[pulseOutput] != 0U))
    {
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    if (outputMode == PLSR_OUTPUT_AB)
    {
        PLSR_AB_SETTING pending;

        PlsrPlatformToAbSetting(setting, &pending);
        PlsrAbPendingSetting[pulseOutput] = pending;
        PlsrAbFrequencyPending[pulseOutput] =
            ((setting->prescaler
              != PlsrAbActiveSetting[pulseOutput].basePrescaler)
             || (setting->pairPrescaler
                 != PlsrAbActiveSetting[pulseOutput].pairPrescaler)
             || (setting->period
                 != PlsrAbActiveSetting[pulseOutput].period)) ? 1U : 0U;
    }
    else
    {
        TIM_TypeDef *timer = PlsrTimerMap[pulseOutput].timer;

        if ((timer->CR1 & TIM_CR1_CEN) == 0UL)
        {
            return PLSR_PLATFORM_QUEUE_STALE;
        }
        timer->PSC = setting->prescaler;
        timer->ARR = setting->period;
        timer->CCR1 = setting->compare;
        __DMB();
    }
    PlsrTimerQueuedSetting[pulseOutput] = *setting;
    PlsrTimerQueuedFrequencyHz[pulseOutput] = setting->actualFrequencyHz;
    PlsrTimerQueueGeneration[pulseOutput]++;
    *actualFrequencyHz = setting->actualFrequencyHz;
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

void PlsrPlatformGateFromIrq(uint8_t pulseOutput)
{
    if ((pulseOutput <= 3U)
        && (PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        && (PlsrAbFastGated[pulseOutput] != 0U))
    {
        return;
    }
    PlsrPlatformStopPulse(pulseOutput);
}

PLSR_PLATFORM_QUEUE_RESULT PlsrPlatformQueueFrequency(
    uint8_t pulseOutput,
    uint32_t frequencyHz,
    uint32_t *actualFrequencyHz)
{
    TIM_TypeDef *timer;
    PLSR_PLATFORM_TIMER_SETTING setting;
    uint32_t activePeriod;
    uint32_t counter;
    uint32_t criticalState;
    uint32_t ownGeneration;
    uint8_t updatePending;

    if ((pulseOutput > 3U) || (actualFrequencyHz == NULL)
        || (PlsrPlatformBuildTimerSetting(
                pulseOutput, PlsrTimerOutputMode[pulseOutput], frequencyHz,
                &setting) == 0U))
    {
        return PLSR_PLATFORM_QUEUE_FAILED;
    }
    if (PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
    {
        PLSR_AB_SETTING pending;
        uint32_t criticalState;

        if ((PlsrTimerRunning[pulseOutput] == 0U)
            || (PlsrAbStopPending[pulseOutput] != 0U)
            || (PlsrAbFastGated[pulseOutput] != 0U))
        {
            return PLSR_PLATFORM_QUEUE_STALE;
        }
        criticalState = PlsrPlatformEnterCritical();
        if ((PlsrTimerRunning[pulseOutput] == 0U)
            || (PlsrAbStopPending[pulseOutput] != 0U)
            || (PlsrAbFastGated[pulseOutput] != 0U))
        {
            PlsrPlatformExitCritical(criticalState);
            return PLSR_PLATFORM_QUEUE_STALE;
        }
        PlsrPlatformToAbSetting(&setting, &pending);
        PlsrAbPendingSetting[pulseOutput] = pending;
        PlsrAbFrequencyPending[pulseOutput] =
            ((pending.basePrescaler
              != PlsrAbActiveSetting[pulseOutput].basePrescaler)
             || (pending.pairPrescaler
                 != PlsrAbActiveSetting[pulseOutput].pairPrescaler)
             || (pending.period
                 != PlsrAbActiveSetting[pulseOutput].period)) ? 1U : 0U;
        PlsrTimerQueuedSetting[pulseOutput] = setting;
        PlsrTimerQueuedFrequencyHz[pulseOutput] = setting.actualFrequencyHz;
        PlsrTimerQueueGeneration[pulseOutput]++;
        *actualFrequencyHz = setting.actualFrequencyHz;
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_APPLIED;
    }

    timer = PlsrTimerMap[pulseOutput].timer;
    if ((timer->CR1 & TIM_CR1_CEN) == 0UL)
    {
        return PLSR_PLATFORM_QUEUE_STALE;
    }

    criticalState = PlsrPlatformEnterCritical();
    if ((timer->SR & TIM_SR_UIF) != 0UL)
    {
        *actualFrequencyHz = PlsrTimerQueuedFrequencyHz[pulseOutput];
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    activePeriod = PlsrTimerActiveSetting[pulseOutput].period;
    counter = timer->CNT;
    if ((counter > activePeriod)
        || ((activePeriod - counter) < PLSR_QUEUE_WRITE_GUARD_COUNTS))
    {
        *actualFrequencyHz = PlsrTimerQueuedFrequencyHz[pulseOutput];
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_STALE;
    }

    /* Preserve real update events and their TRGO pulse while replacing the
       three preload registers. The near-wrap guard bounds the write window. */
    timer->PSC = setting.prescaler;
    timer->ARR = setting.period;
    timer->CCR1 = setting.compare;
    __DMB();
    updatePending = ((timer->SR & TIM_SR_UIF) != 0UL) ? 1U : 0U;
    PlsrTimerQueuedFrequencyHz[pulseOutput] = setting.actualFrequencyHz;
    PlsrTimerQueuedSetting[pulseOutput] = setting;
    PlsrTimerQueueGeneration[pulseOutput]++;
    ownGeneration = PlsrTimerQueueGeneration[pulseOutput];
    if (updatePending != 0U)
    {
        *actualFrequencyHz = PlsrTimerQueuedFrequencyHz[pulseOutput];
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    *actualFrequencyHz =
        (PlsrTimerQueueGeneration[pulseOutput] == ownGeneration)
            ? setting.actualFrequencyHz
            : PlsrTimerQueuedFrequencyHz[pulseOutput];
    if (PlsrTimerQueueGeneration[pulseOutput] != ownGeneration)
    {
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_QUEUE_STALE;
    }
    PlsrPlatformExitCritical(criticalState);
    return PLSR_PLATFORM_QUEUE_APPLIED;
}

void PlsrPlatformDrainPendingPulse(uint8_t pulseOutput)
{
    if (pulseOutput <= 3U)
    {
        if ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
            && (PlsrDeferredPulsePending[pulseOutput] != 0U))
        {
            uint8_t verifyOutput =
                (PlsrAbLagAxis[pulseOutput] == pulseOutput)
                    ? (uint8_t)(pulseOutput + 1U) : pulseOutput;
            TIM_TypeDef *verifyTimer = PlsrTimerMap[verifyOutput].timer;

            verifyTimer->DIER &= ~(TIM_DIER_UIE | TIM_DIER_CC1IE);
            verifyTimer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
            PlsrAbVerifyOwner[verifyOutput] = PLSR_COUNTER_NONE;
            if (PlsrFrequencyVerifyPending[pulseOutput]
                == PLSR_FREQUENCY_VERIFY_AB_AUX_IRQ)
            {
                PlsrFrequencyVerifyPending[pulseOutput] =
                    PLSR_FREQUENCY_VERIFY_NONE;
                PlsrFrequencyVerifyPulseCount[pulseOutput] = 0U;
                (void)PlsrVerifyActiveFrequency(pulseOutput);
            }
            PlsrDeferredPulsePending[pulseOutput] = 0U;
            PlsrPulseTimerIrq(pulseOutput);
            return;
        }
        PlsrHandleTimerIrq(pulseOutput);
    }
}

uint32_t PlsrPlatformActiveFrequency(uint8_t pulseOutput)
{
    if (pulseOutput > 3U)
    {
        return 0UL;
    }
    if ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        && (PlsrAbFastGated[pulseOutput] != 0U))
    {
        PlsrFrequencyVerifyPending[pulseOutput] =
            PLSR_FREQUENCY_VERIFY_NONE;
        PlsrFrequencyVerifyPulseCount[pulseOutput] = 0U;
        return PlsrTimerActiveFrequencyHz[pulseOutput];
    }
    if (PlsrFrequencyVerifyPending[pulseOutput]
        == PLSR_FREQUENCY_VERIFY_AB_AUX_IRQ)
    {
        return PlsrTimerActiveFrequencyHz[pulseOutput];
    }
    if (PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
    {
        PlsrFrequencyVerifyPulseCount[pulseOutput]++;
        if (PlsrFrequencyVerifyPulseCount[pulseOutput]
            >= PLSR_STRUCTURE_VERIFY_INTERVAL)
        {
            PlsrFrequencyVerifyPulseCount[pulseOutput] = 0U;
            PlsrAbScheduleFrequencyVerify(pulseOutput);
        }
        return PlsrTimerActiveFrequencyHz[pulseOutput];
    }
    if (PlsrFrequencyVerifyPending[pulseOutput]
        == PLSR_FREQUENCY_VERIFY_NOW)
    {
        PlsrFrequencyVerifyPending[pulseOutput] =
            PLSR_FREQUENCY_VERIFY_NONE;
        PlsrFrequencyVerifyPulseCount[pulseOutput] = 0U;
        return PlsrVerifyActiveFrequency(pulseOutput);
    }
    PlsrFrequencyVerifyPulseCount[pulseOutput]++;
    if (PlsrFrequencyVerifyPulseCount[pulseOutput]
        >= PLSR_STRUCTURE_VERIFY_INTERVAL)
    {
        PlsrFrequencyVerifyPulseCount[pulseOutput] = 0U;
        return PlsrVerifyActiveFrequency(pulseOutput);
    }
    return PlsrTimerActiveFrequencyHz[pulseOutput];
}

uint8_t PlsrPlatformExpectedFrequency(uint8_t pulseOutput,
                                      uint8_t outputMode,
                                      uint32_t requestedFrequencyHz,
                                      uint32_t *actualFrequencyHz)
{
    PLSR_PLATFORM_TIMER_SETTING setting;

    if (actualFrequencyHz == NULL)
    {
        return 0U;
    }
    if (PlsrPlatformBuildTimerSetting(pulseOutput, outputMode,
                                      requestedFrequencyHz,
                                      &setting) == 0U)
    {
        return 0U;
    }
    *actualFrequencyHz = setting.actualFrequencyHz;
    return 1U;
}

uint64_t PlsrPlatformObservedPulses(uint8_t pulseOutput)
{
    uint32_t criticalState;
    uint64_t observed;

    if (pulseOutput > 3U)
    {
        return 0UL;
    }
    criticalState = PlsrPlatformEnterCritical();
    if (PlsrCounterIndexByOutput[pulseOutput] < PLSR_COUNTER_COUNT)
    {
        observed = ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
                    && (PlsrAbFastGated[pulseOutput] != 0U))
                       ? PlsrCounterSnapshotStopped(pulseOutput)
                       : PlsrCounterSnapshot(pulseOutput);
    }
    else
    {
        observed = PlsrObservedPulseBase[pulseOutput];
    }
    PlsrPlatformExitCritical(criticalState);
    return observed;
}

uint16_t PlsrPlatformDiagnosticFault(void)
{
    uint16_t fault = PlsrPlatformFaultPending;

    PlsrPlatformFaultPending = 0U;
    return fault;
}

PLSR_PLATFORM_STOP_RESULT PlsrPlatformRequestStopLocked(
    uint8_t pulseOutput,
    uint8_t requireZeroBoundary)
{
    if (pulseOutput > 3U)
    {
        return PLSR_PLATFORM_STOP_FORCED_FAULT;
    }
    if ((requireZeroBoundary != 0U)
        && (PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        && (PlsrTimerRunning[pulseOutput] != 0U)
        && (PlsrAbFastGated[pulseOutput] == 0U))
    {
        uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
        uint8_t lagOutput = PlsrAbLagAxis[pulseOutput];
        uint32_t activeFrequencyHz;
        TIM_TypeDef *baseTimer = PlsrTimerMap[pulseOutput].timer;
        TIM_TypeDef *pairTimer = PlsrTimerMap[pairOutput].timer;
        uint8_t structureRunnable =
            ((PlsrAbStructureVerified[pulseOutput] != 0U)
             && (PlsrFrequencyVerifyPending[pulseOutput]
                 == PLSR_FREQUENCY_VERIFY_NONE))
                ? PlsrAbStopBoundaryIsReachable(pulseOutput, baseTimer,
                                                pairTimer)
                : PlsrAbTimersAreRunnable(pulseOutput, baseTimer,
                                          pairTimer);

        if (structureRunnable == 0U)
        {
            PlsrCounterSuspend(pulseOutput);
            PlsrAbHoldPairIdle(pulseOutput);
            baseTimer->CR1 &= ~TIM_CR1_CEN;
            pairTimer->CR1 &= ~TIM_CR1_CEN;
            __DMB();
            PlsrPlatformStopPulse(pulseOutput);
            return PLSR_PLATFORM_STOP_FORCED_FAULT;
        }
        if (PlsrAbStopPending[pulseOutput] != 0U)
        {
            return PLSR_PLATFORM_STOP_PENDING;
        }

        PlsrAbFrequencyPending[pulseOutput] = 0U;
        baseTimer->DIER &= ~TIM_DIER_UIE;
        pairTimer->DIER &= ~TIM_DIER_UIE;
        PlsrFrequencyVerifyPending[pulseOutput] =
            PLSR_FREQUENCY_VERIFY_NONE;
        PlsrFrequencyVerifyPulseCount[pulseOutput] = 0U;
        PlsrAbVerifyOwner[pulseOutput] = PLSR_COUNTER_NONE;
        PlsrAbVerifyOwner[pairOutput] = PLSR_COUNTER_NONE;
        activeFrequencyHz = PlsrTimerActiveFrequencyHz[pulseOutput];
        PlsrTimerQueuedFrequencyHz[pulseOutput] = activeFrequencyHz;
        PlsrTimerQueueGeneration[pulseOutput]++;
        PlsrAbStopPending[pulseOutput] = 1U;
#if PLSR_DEBUG_TIMING
        if (PlsrFinalArmQueueTimingPending[pulseOutput] != 0U)
        {
            uint32_t queuedAt = PlsrFinalArmQueuedAt[pulseOutput];
            uint32_t stoppedAt = DWT->CYCCNT;
            uint32_t latency = stoppedAt - queuedAt;

            PlsrFinalArmQueueTimingPending[pulseOutput] = 0U;
            PlsrFinalArmQueueToStopLastCycles[pulseOutput] = latency;
            if (latency > PlsrFinalArmQueueToStopMaxCycles[pulseOutput])
            {
                PlsrFinalArmQueueToStopMaxCycles[pulseOutput] = latency;
            }
        }
#endif
        if (lagOutput == pulseOutput)
        {
            pairTimer->SR = ~TIM_SR_CC1IF;
        }
        else
        {
            baseTimer->SR = ~TIM_SR_CC1IF;
        }
        baseTimer->DIER |= TIM_DIER_CC1IE;
        pairTimer->DIER |= TIM_DIER_CC1IE;
        __DMB();
        return PLSR_PLATFORM_STOP_PENDING;
    }
    PlsrPlatformStopPulse(pulseOutput);
    return PLSR_PLATFORM_STOP_COMPLETE;
}

uint8_t PlsrPlatformQueueFinalArmFromIrq(uint8_t pulseOutput)
{
    uint8_t jobOutput;

    if ((pulseOutput > 2U) || ((pulseOutput & 1U) != 0U)
        || (PlsrTimerOutputMode[pulseOutput] != PLSR_OUTPUT_AB)
        || (PlsrTimerRunning[pulseOutput] == 0U)
        || (PlsrAbFastGated[pulseOutput] != 0U))
    {
        return 0U;
    }
    jobOutput = PlsrFinalArmJobOutput(pulseOutput);
    if (PlsrAbFinalArmJobOwner[jobOutput] != PLSR_COUNTER_NONE)
    {
        return 0U;
    }
    PlsrAbFinalArmJobOwner[jobOutput] = pulseOutput;
#if PLSR_DEBUG_TIMING
    PlsrFinalArmQueuedAt[pulseOutput] = DWT->CYCCNT;
    PlsrFinalArmQueueTimingPending[pulseOutput] = 1U;
    PlsrFinalArmQueueCount[pulseOutput]++;
#endif
    __DMB();
    NVIC_SetPendingIRQ(PlsrTimerMap[jobOutput].irq);
    return 1U;
}

void PlsrPlatformStopPulse(uint8_t pulseOutput)
{
    if (pulseOutput <= 3U)
    {
        PlsrFiniteActive[pulseOutput] = 0U;
        PlsrFiniteCompletionPending[pulseOutput] = 0U;
        PlsrFiniteFrequencyPending[pulseOutput] = 0U;
        PlsrFiniteRetargetPending[pulseOutput] = 0U;
        PlsrFiniteTailStopPending[pulseOutput] = 0U;
        PlsrFiniteRetargetDrainPulses[pulseOutput] = 0UL;
        PlsrFiniteTargetPulses[pulseOutput] = 0UL;
        PlsrFiniteRemainingPulses[pulseOutput] = 0UL;
        PlsrFiniteStreamActive[pulseOutput] = 0U;
        PlsrFiniteStreamNextValid[pulseOutput] = 0U;
        PlsrFiniteStreamNextStartsSegment[pulseOutput] = 0U;
        PlsrFiniteStreamSourceDone[pulseOutput] = 0U;
        PlsrFiniteStreamSourceFault[pulseOutput] = 0U;
        if (PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        {
            uint8_t pairOutput = (uint8_t)(pulseOutput + 1U);
            uint8_t jobOutput = PlsrFinalArmJobOutput(pulseOutput);
            TIM_TypeDef *baseTimer = PlsrTimerMap[pulseOutput].timer;
            TIM_TypeDef *pairTimer = PlsrTimerMap[pairOutput].timer;

            PlsrAbStructureVerified[pulseOutput] = 0U;
            PlsrAbFinalArmJobOwner[jobOutput] = PLSR_COUNTER_NONE;
#if PLSR_DEBUG_TIMING
            PlsrFinalArmQueueTimingPending[pulseOutput] = 0U;
#endif
            NVIC_ClearPendingIRQ(PlsrTimerMap[jobOutput].irq);
            if (PlsrAbFastGated[pulseOutput] != 0U)
            {
                PlsrAbHoldPairIdle(pulseOutput);
                baseTimer->DIER = 0UL;
                pairTimer->DIER = 0UL;
                baseTimer->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
                pairTimer->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
                baseTimer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
                pairTimer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
            }
            else
            {
                PlsrCounterSuspend(pulseOutput);
                PlsrAbHoldPairIdle(pulseOutput);
                PlsrTimerStop(baseTimer);
                PlsrTimerStop(pairTimer);
            }
        }
        else
        {
            PlsrPulsePinCaptureIdle(pulseOutput);
            PlsrTimerStop(PlsrTimerMap[pulseOutput].timer);
        }
        PlsrCounterStop(pulseOutput);
        PlsrTimerActiveFrequencyHz[pulseOutput] = 0UL;
        PlsrTimerQueuedFrequencyHz[pulseOutput] = 0UL;
        PlsrTimerQueueGeneration[pulseOutput]++;
        PlsrTimerRunning[pulseOutput] = 0U;
        PlsrFrequencyVerifyPending[pulseOutput] = 0U;
        PlsrDeferredPulsePending[pulseOutput] = 0U;
        PlsrAbVerifyOwner[pulseOutput] = PLSR_COUNTER_NONE;
        if (PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_AB)
        {
            PlsrAbVerifyOwner[pulseOutput + 1U] = PLSR_COUNTER_NONE;
        }
        PlsrAbFrequencyPending[pulseOutput] = 0U;
        PlsrAbStopPending[pulseOutput] = 0U;
        PlsrAbFastGated[pulseOutput] = 0U;
    }
}

void PlsrPlatformForceSafeOutputsFromFault(void)
{
    uint32_t mode;
    const uint32_t outputPins = GPIO_PIN_6 | GPIO_PIN_7
                                | GPIO_PIN_8 | GPIO_PIN_9;
    const uint32_t outputModeMask = (3UL << (6U * 2U))
                                    | (3UL << (7U * 2U))
                                    | (3UL << (8U * 2U))
                                    | (3UL << (9U * 2U));

    __disable_irq();

    TIM10->DIER = 0UL;
    TIM10->CR1 &= ~TIM_CR1_CEN;
    TIM10->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
    TIM10->SR = 0UL;
    TIM11->DIER = 0UL;
    TIM11->CR1 &= ~TIM_CR1_CEN;
    TIM11->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
    TIM11->SR = 0UL;
    TIM13->DIER = 0UL;
    TIM13->CR1 &= ~TIM_CR1_CEN;
    TIM13->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
    TIM13->SR = 0UL;
    TIM14->DIER = 0UL;
    TIM14->CR1 &= ~TIM_CR1_CEN;
    TIM14->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
    TIM14->SR = 0UL;

    TIM9->DIER = 0UL;
    TIM9->CR1 &= ~TIM_CR1_CEN;
    TIM9->SMCR = 0UL;
    TIM9->SR = 0UL;
    TIM12->DIER = 0UL;
    TIM12->CR1 &= ~TIM_CR1_CEN;
    TIM12->SMCR = 0UL;
    TIM12->SR = 0UL;

    RCC->AHB1ENR |= RCC_AHB1ENR_GPIOFEN | RCC_AHB1ENR_GPIOHEN;
    __DSB();
    GPIOF->BSRR = outputPins;
    GPIOH->BSRR = outputPins;
    GPIOF->OTYPER &= ~outputPins;
    GPIOH->OTYPER &= ~outputPins;
    GPIOF->PUPDR &= ~outputModeMask;
    GPIOH->PUPDR &= ~outputModeMask;
    mode = GPIOF->MODER;
    mode &= ~outputModeMask;
    mode |= (1UL << (6U * 2U)) | (1UL << (7U * 2U))
            | (1UL << (8U * 2U)) | (1UL << (9U * 2U));
    GPIOF->MODER = mode;
    mode = GPIOH->MODER;
    mode &= ~outputModeMask;
    mode |= (1UL << (6U * 2U)) | (1UL << (7U * 2U))
            | (1UL << (8U * 2U)) | (1UL << (9U * 2U));
    GPIOH->MODER = mode;
    __DSB();
}

uint8_t PlsrPlatformReadInput(uint8_t inputSelection)
{
    if (inputSelection == 0U)
    {
        return (HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_5) == GPIO_PIN_SET) ? 1U : 0U;
    }
    if (inputSelection == 1U)
    {
        return (HAL_GPIO_ReadPin(GPIOG, GPIO_PIN_12) == GPIO_PIN_SET) ? 1U : 0U;
    }
    return 0U;
}

uint8_t PlsrPlatformLoad(PLSR_PERSIST_PAYLOAD *payload)
{
    PLSR_FLASH_SECTOR_SCAN scanA;
    PLSR_FLASH_SECTOR_SCAN scanB;
    const PLSR_FLASH_HEADER *selected = NULL;
    const void *backupConfig = (const void *)PLSR_BACKUP_CONFIG_ADDRESS;
    const PLSR_BACKUP_POSITION_RECORD *backupPosition;
    uint8_t selectedVersion = 0U;
    uint8_t backupVersion;
    uint8_t haveConfig = 0U;
    uint32_t selectedSectorAddress;

    if (payload == NULL)
    {
        return 0U;
    }

    selected = PlsrFlashInitializeJournal(&scanA, &scanB, &selectedVersion,
                                          &selectedSectorAddress);

    if (selected != NULL)
    {
        if (selectedVersion == PLSR_FLASH_VERSION)
        {
            *payload = ((const PLSR_FLASH_RECORD *)selected)->payload;
        }
        else
        {
            PlsrLoadV2Payload(
                payload,
                &((const PLSR_FLASH_RECORD_V2 *)selected)->payload);
        }
        haveConfig = 1U;
    }
    else
    {
        (void)memset(payload, 0, sizeof(*payload));
    }

    backupVersion = PlsrBackupConfigVersion(backupConfig);
    if (backupVersion == PLSR_FLASH_VERSION)
    {
        payload->config =
            ((const PLSR_BACKUP_CONFIG_RECORD *)backupConfig)->config;
        haveConfig = 1U;
    }
    else if (backupVersion == PLSR_FLASH_VERSION_V2)
    {
        const PLSR_BACKUP_CONFIG_RECORD_V2 *oldConfig =
            (const PLSR_BACKUP_CONFIG_RECORD_V2 *)backupConfig;

        (void)memcpy(&payload->config, oldConfig->config,
                     sizeof(oldConfig->config));
        payload->config.outputMode = PLSR_OUTPUT_PULSE_DIR;
        haveConfig = 1U;
    }
    backupPosition = PlsrNewestBackupPosition();
    if (backupPosition != NULL)
    {
        payload->position = backupPosition->position;
        payload->positionValid = backupPosition->positionValid;
        payload->wasBusy = backupPosition->wasBusy;
    }

    if (selected != NULL)
    {
        uint8_t reserveIndex =
            (selectedSectorAddress == PLSR_FLASH_SLOT_A_ADDRESS) ? 1U : 0U;
        const PLSR_FLASH_SECTOR_SCAN *reserveScan =
            (reserveIndex == 0U) ? &scanA : &scanB;

        if (reserveScan->hasProgrammedSlot != 0U)
        {
            PlsrFlashReserveEraseState = (uint8_t)(reserveIndex + 1U);
        }
    }
    else if (PlsrFlashNeedsStartupRecovery(
                 0U,
                 scanA.hasProgrammedSlot,
                 scanA.firstErasedAddress,
                 scanB.hasProgrammedSlot,
                 scanB.firstErasedAddress) != 0U)
    {
        PlsrFlashReserveEraseState = PLSR_FLASH_ERASE_SECTOR_A;
    }
    return haveConfig;
}

PLSR_PLATFORM_SERVICE_RESULT PlsrPlatformServicePersistence(void)
{
    uint32_t criticalState;
    uint8_t eraseState;
    uint8_t sectorIndex;
    uint8_t index;

    criticalState = PlsrPlatformEnterCritical();
    eraseState = PlsrFlashReserveEraseState;
    if (eraseState == PLSR_FLASH_ERASE_FAILED)
    {
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_SERVICE_FAILED;
    }
    if (eraseState == PLSR_FLASH_ERASE_NONE)
    {
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_SERVICE_READY;
    }
    if ((eraseState < PLSR_FLASH_ERASE_SECTOR_A)
        || (eraseState > PLSR_FLASH_ERASE_SECTOR_B))
    {
        PlsrFlashReserveEraseState = PLSR_FLASH_ERASE_FAILED;
        PlsrPlatformExitCritical(criticalState);
        return PLSR_PLATFORM_SERVICE_FAILED;
    }
    for (index = 0U; index < 4U; index++)
    {
        if ((PlsrTimerRunning[index] != 0U)
            || (PlsrTimerIrqActive[index] != 0U))
        {
            PlsrPlatformExitCritical(criticalState);
            return PLSR_PLATFORM_SERVICE_DEFERRED;
        }
    }
    sectorIndex = (uint8_t)(eraseState - PLSR_FLASH_ERASE_SECTOR_A);
    PlsrPlatformExitCritical(criticalState);

    if (PlsrFlashEraseReserve(sectorIndex) == 0U)
    {
        PlsrFlashReserveEraseState = PLSR_FLASH_ERASE_FAILED;
        return PLSR_PLATFORM_SERVICE_FAILED;
    }

    PlsrFlashNextErasedAddress[sectorIndex] =
        (sectorIndex == 0U) ? PLSR_FLASH_SLOT_A_ADDRESS
                            : PLSR_FLASH_SLOT_B_ADDRESS;
    PlsrFlashReserveEraseState = PLSR_FLASH_ERASE_NONE;
    return PLSR_PLATFORM_SERVICE_READY;
}

uint8_t PlsrPlatformSave(const PLSR_PERSIST_PAYLOAD *payload)
{
    PLSR_FLASH_SECTOR_SCAN scanA;
    PLSR_FLASH_SECTOR_SCAN scanB;
    uint8_t newestVersion;
    uint32_t newestSectorAddress;
    uint8_t targetIndex;
    uint32_t targetAddress;
    uint32_t index;
    uint32_t wordCount;
    const uint32_t *words;
    HAL_StatusTypeDef status = HAL_OK;

    if (payload == NULL)
    {
        return 0U;
    }

    if (PlsrFlashJournalInitialized == 0U)
    {
        (void)PlsrFlashInitializeJournal(&scanA, &scanB, &newestVersion,
                                         &newestSectorAddress);
        (void)newestVersion;
        (void)newestSectorAddress;
    }

    if (PlsrFlashNewestAddress != 0UL)
    {
        targetIndex = PlsrFlashSectorIndex(PlsrFlashNewestAddress);
        if (PlsrFlashNextErasedAddress[targetIndex] == 0UL)
        {
            targetIndex ^= 1U;
        }
    }
    else if (PlsrFlashNextErasedAddress[0] != 0UL)
    {
        targetIndex = 0U;
    }
    else
    {
        targetIndex = 1U;
    }

    targetAddress = PlsrFlashNextErasedAddress[targetIndex];
    if ((targetAddress != 0UL)
        && ((PlsrFlashAddressIsJournalSlot(targetIndex, targetAddress) == 0U)
            || (PlsrFlashSlotIsErased(targetAddress) == 0U)))
    {
        targetAddress = 0UL;
        PlsrFlashNextErasedAddress[targetIndex] = 0UL;
    }
    if (targetAddress == 0UL)
    {
        uint8_t newestIndex = (PlsrFlashNewestAddress != 0UL)
                                  ? PlsrFlashSectorIndex(
                                        PlsrFlashNewestAddress)
                                  : 0xFFU;
        uint8_t alternateIndex = targetIndex ^ 1U;

        if ((targetIndex == newestIndex)
            || (PlsrFlashNextErasedAddress[alternateIndex] != 0UL))
        {
            targetIndex = alternateIndex;
            targetAddress = PlsrFlashNextErasedAddress[targetIndex];
            if ((targetAddress != 0UL)
                && ((PlsrFlashAddressIsJournalSlot(targetIndex,
                                                    targetAddress) == 0U)
                    || (PlsrFlashSlotIsErased(targetAddress) == 0U)))
            {
                targetAddress = 0UL;
                PlsrFlashNextErasedAddress[targetIndex] = 0UL;
            }
        }
        if (targetAddress == 0UL)
        {
            return 0U;
        }
    }

    PlsrFlashNextErasedAddress[targetIndex] =
        PlsrFlashFindErasedAfter(targetIndex, targetAddress);

    (void)memset(&PlsrFlashRecordBuffer, 0, sizeof(PlsrFlashRecordBuffer));
    PlsrFlashRecordBuffer.magic = PLSR_FLASH_MAGIC;
    PlsrFlashRecordBuffer.version = PLSR_FLASH_VERSION;
    PlsrFlashRecordBuffer.payloadSize = sizeof(PLSR_PERSIST_PAYLOAD);
    PlsrFlashRecordBuffer.generation = PlsrFlashNewestGeneration + 1UL;
    PlsrFlashRecordBuffer.payload = *payload;
    PlsrFlashRecordBuffer.crc32 =
        PlsrFlashRecordCrc(&PlsrFlashRecordBuffer,
                           sizeof(PlsrFlashRecordBuffer.payload));

    if (HAL_FLASH_Unlock() != HAL_OK)
    {
        (void)HAL_FLASH_Lock();
        return 0U;
    }
    __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR
                           | FLASH_FLAG_PGAERR | FLASH_FLAG_PGPERR
                           | FLASH_FLAG_PGSERR);
    words = (const uint32_t *)&PlsrFlashRecordBuffer;
    wordCount = sizeof(PlsrFlashRecordBuffer) / sizeof(uint32_t);
    if (status == HAL_OK)
    {
        for (index = 1UL; index < wordCount; index++)
        {
            if (HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD,
                                  targetAddress + index * 4UL,
                                  words[index]) != HAL_OK)
            {
                status = HAL_ERROR;
                break;
            }
        }
    }
    if ((status == HAL_OK)
        && (HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, targetAddress,
                              PLSR_FLASH_MAGIC) != HAL_OK))
    {
        status = HAL_ERROR;
    }
    if (HAL_FLASH_Lock() != HAL_OK)
    {
        (void)HAL_FLASH_Lock();
        status = HAL_ERROR;
    }

    if (PlsrFlashRecordVersion((const void *)targetAddress)
        == PLSR_FLASH_VERSION)
    {
        PlsrFlashNewestAddress = targetAddress;
        PlsrFlashNewestGeneration = PlsrFlashRecordBuffer.generation;
        return (status == HAL_OK) ? 1U : 0U;
    }
    return 0U;
}

void PlsrPlatformCheckpointConfig(const PLSR_CONFIG *config)
{
    PLSR_BACKUP_CONFIG_RECORD *record =
        (PLSR_BACKUP_CONFIG_RECORD *)PLSR_BACKUP_CONFIG_ADDRESS;

    if (config == NULL)
    {
        return;
    }
    record->magic = 0UL;
    record->config = *config;
    record->crc32 = PlsrCrc32(&record->config, sizeof(record->config));
    __DMB();
    record->magic = PLSR_BACKUP_CONFIG_MAGIC;
    __DMB();
}

void PlsrPlatformCheckpointPosition(int32_t position,
                                    uint8_t positionValid,
                                    uint8_t wasBusy)
{
    PLSR_BACKUP_POSITION_RECORD *slots =
        (PLSR_BACKUP_POSITION_RECORD *)PLSR_BACKUP_POSITION_ADDRESS;
    PLSR_BACKUP_POSITION_RECORD *record;

    PlsrBackupPositionGeneration++;
    record = &slots[PlsrBackupPositionGeneration & 1UL];
    record->magic = 0UL;
    record->generation = PlsrBackupPositionGeneration;
    record->position = position;
    record->positionValid = (positionValid != 0U) ? 1U : 0U;
    record->wasBusy = (wasBusy != 0U) ? 1U : 0U;
    record->reserved = 0U;
    record->crc32 = PlsrCrc32(&record->generation,
                              sizeof(record->generation)
                              + sizeof(record->position)
                              + sizeof(record->positionValid)
                              + sizeof(record->wasBusy)
                              + sizeof(record->reserved));
    __DMB();
    record->magic = PLSR_BACKUP_POSITION_MAGIC;
    __DMB();
}

uint32_t PlsrPlatformEnterCritical(void)
{
    uint32_t state = __get_PRIMASK();
    __disable_irq();
    __DMB();
    return state;
}

void PlsrPlatformExitCritical(uint32_t state)
{
    __DMB();
    if (state == 0UL)
    {
        __enable_irq();
    }
}

static void PlsrHandleTimerIrq(uint8_t pulseOutput)
{
    TIM_TypeDef *timer;
#if PLSR_DEBUG_TIMING
    uint32_t startedAt;
    uint32_t elapsedCycles;
    uint8_t timingOutput = pulseOutput;

    startedAt = DWT->CYCCNT;
#endif
    timer = PlsrTimerMap[pulseOutput].timer;

    if (PlsrTimerIrqActive[pulseOutput] != 0U)
    {
#if PLSR_DEBUG_TIMING
        goto irq_record;
#else
        return;
#endif
    }
    PlsrTimerIrqActive[pulseOutput] = 1U;

    if (((timer->SR & TIM_SR_CC1IF) != 0UL)
        && ((timer->DIER & TIM_DIER_CC1IE) != 0UL))
    {
        uint8_t owner = ((pulseOutput & 2U) == 0U) ? 0U : 2U;

        if ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_PULSE_DIR)
            && (PlsrFiniteRetargetPending[pulseOutput] != 0U))
        {
            timer->SR = ~TIM_SR_CC1IF;
            PlsrFiniteRetargetAtFallingEdge(pulseOutput);
            goto irq_done;
        }
        if ((PlsrTimerOutputMode[pulseOutput] == PLSR_OUTPUT_PULSE_DIR)
            && (PlsrFiniteTailStopPending[pulseOutput] != 0U))
        {
            timer->SR = ~TIM_SR_CC1IF;
            PlsrFiniteStopAtFallingEdge(pulseOutput);
            goto irq_done;
        }
#if PLSR_DEBUG_TIMING
        timingOutput = owner;
#endif
        timer->SR = ~TIM_SR_CC1IF;
        if ((owner <= 2U)
            && (PlsrTimerRunning[owner] != 0U)
            && (PlsrTimerOutputMode[owner] == PLSR_OUTPUT_AB))
        {
            uint8_t pairOutput = (uint8_t)(owner + 1U);
            TIM_TypeDef *baseTimer = PlsrTimerMap[owner].timer;
            TIM_TypeDef *pairTimer = PlsrTimerMap[pairOutput].timer;
            PLSR_AB_SETTING pending;

            if (PlsrAbStopPending[owner] != 0U)
            {
                if (PlsrAbCanFastGateAtZero(owner) == 0U)
                {
                    goto irq_done;
                }
                baseTimer->DIER &= ~(TIM_DIER_CC1IE | TIM_DIER_UIE);
                pairTimer->DIER &= ~(TIM_DIER_CC1IE | TIM_DIER_UIE);
                baseTimer->SR = ~TIM_SR_CC1IF;
                pairTimer->SR = ~TIM_SR_CC1IF;
                PlsrFrequencyVerifyPending[owner] =
                    PLSR_FREQUENCY_VERIFY_NONE;
                PlsrAbVerifyOwner[owner] = PLSR_COUNTER_NONE;
                PlsrAbVerifyOwner[pairOutput] = PLSR_COUNTER_NONE;
                PlsrAbFastGate(owner);
                PlsrAbFastGated[owner] = 1U;
                PlsrDeferredPulsePending[owner] = 0U;
                PlsrPulseTimerIrq(owner);
                goto irq_done;
            }
            if (pulseOutput != PlsrAbLagAxis[owner])
            {
                if (PlsrDeferredPulsePending[owner] != 0U)
                {
                    PlsrDeferredPulsePending[owner] = 0U;
                    timer->DIER &= ~TIM_DIER_CC1IE;
                    PlsrPulseTimerIrq(owner);
                }
                goto irq_done;
            }
            if (PlsrDeferredPulsePending[owner] != 0U)
            {
                goto irq_done;
            }
            if (PlsrAbFrequencyPending[owner] != 0U)
            {
                pending = PlsrAbPendingSetting[owner];
                PlsrAbFrequencyPending[owner] = 0U;
                PlsrAbLoadAndStart(owner, &pending);
                PlsrAbActiveSetting[owner] = pending;
                PlsrTimerActiveSetting[owner] =
                    PlsrTimerQueuedSetting[owner];
                PlsrTimerActiveFrequencyHz[owner] =
                    pending.actualFrequencyHz;
                PlsrDeferredPulsePending[owner] = 1U;
                PlsrAbScheduleFrequencyVerify(owner);
                goto irq_done;
            }
            PlsrPulseTimerIrq(owner);
        }
        goto irq_done;
    }

    if (((timer->SR & TIM_SR_UIF) != 0UL)
        && ((timer->DIER & TIM_DIER_UIE) != 0UL))
    {
        timer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
        if ((PlsrFiniteActive[pulseOutput] != 0U)
            && (PlsrFiniteFrequencyPending[pulseOutput] != 0U))
        {
            PlsrTimerActiveFrequencyHz[pulseOutput] =
                PlsrTimerQueuedFrequencyHz[pulseOutput];
            PlsrTimerActiveSetting[pulseOutput] =
                PlsrTimerQueuedSetting[pulseOutput];
            PlsrFiniteFrequencyPending[pulseOutput] = 0U;
            timer->DIER &= ~TIM_DIER_UIE;
            goto irq_done;
        }
        if (PlsrPlatformSettingsDiffer(
                &PlsrTimerActiveSetting[pulseOutput],
                &PlsrTimerQueuedSetting[pulseOutput]) != 0U)
        {
            PlsrFrequencyVerifyPending[pulseOutput] = 1U;
            PlsrTimerActiveFrequencyHz[pulseOutput] =
                PlsrTimerQueuedFrequencyHz[pulseOutput];
            PlsrTimerActiveSetting[pulseOutput] =
                PlsrTimerQueuedSetting[pulseOutput];
        }
        PlsrPulseTimerIrq(pulseOutput);
    }
irq_done:
    PlsrTimerIrqActive[pulseOutput] = 0U;
#if PLSR_DEBUG_TIMING
irq_record:
    elapsedCycles = DWT->CYCCNT - startedAt;
    PlsrIrqCount[timingOutput]++;
    PlsrIrqLastCycles[timingOutput] = elapsedCycles;
    if (elapsedCycles > PlsrIrqMaxCycles[timingOutput])
    {
        PlsrIrqMaxCycles[timingOutput] = elapsedCycles;
    }
#endif
}

static uint8_t PlsrHandleScheduledAbVerify(uint8_t pulseOutput)
{
    uint8_t verifyOwner = PlsrAbVerifyOwner[pulseOutput];
    TIM_TypeDef *timer;
#if PLSR_DEBUG_TIMING
    uint32_t startedAt;
    uint32_t elapsedCycles;
#endif

    if (verifyOwner > 2U)
    {
        return 0U;
    }
    timer = PlsrTimerMap[pulseOutput].timer;
    if (((timer->SR & TIM_SR_UIF) == 0UL)
        || ((timer->DIER & TIM_DIER_UIE) == 0UL))
    {
        return 0U;
    }
#if PLSR_DEBUG_TIMING
    startedAt = DWT->CYCCNT;
#endif
    timer->SR = ~TIM_SR_UIF;
    timer->DIER &= ~TIM_DIER_UIE;
    PlsrAbVerifyOwner[pulseOutput] = PLSR_COUNTER_NONE;
    if (PlsrFrequencyVerifyPending[verifyOwner]
        == PLSR_FREQUENCY_VERIFY_AB_AUX_IRQ)
    {
        PlsrFrequencyVerifyPending[verifyOwner] =
            PLSR_FREQUENCY_VERIFY_NONE;
        PlsrFrequencyVerifyPulseCount[verifyOwner] = 0U;
        (void)PlsrVerifyActiveFrequency(verifyOwner);
    }
#if PLSR_DEBUG_TIMING
    elapsedCycles = DWT->CYCCNT - startedAt;
    PlsrIrqCount[verifyOwner]++;
    PlsrIrqLastCycles[verifyOwner] = elapsedCycles;
    if (elapsedCycles > PlsrIrqMaxCycles[verifyOwner])
    {
        PlsrIrqMaxCycles[verifyOwner] = elapsedCycles;
    }
#endif
    return 1U;
}

static uint8_t PlsrFinalStopIrqIsPending(uint8_t pulseOutput)
{
    uint8_t owner = ((pulseOutput & 2U) == 0U) ? 0U : 2U;
    TIM_TypeDef *timer = PlsrTimerMap[pulseOutput].timer;

    return ((PlsrAbStopPending[owner] != 0U)
            && ((timer->SR & TIM_SR_CC1IF) != 0UL)
            && ((timer->DIER & TIM_DIER_CC1IE) != 0UL)) ? 1U : 0U;
}

static uint8_t PlsrHandleFinalArmJob(uint8_t pulseOutput)
{
    uint8_t owner = PlsrAbFinalArmJobOwner[pulseOutput];
#if PLSR_DEBUG_TIMING
    uint32_t startedAt;
    uint32_t elapsedCycles;
#endif

    if (owner > 2U)
    {
        return 0U;
    }
    PlsrAbFinalArmJobOwner[pulseOutput] = PLSR_COUNTER_NONE;
#if PLSR_DEBUG_TIMING
    startedAt = DWT->CYCCNT;
#endif
    PlsrFinalArmJobIrq(owner);
#if PLSR_DEBUG_TIMING
    elapsedCycles = DWT->CYCCNT - startedAt;
    PlsrFinalArmJobLastCycles[owner] = elapsedCycles;
    if (elapsedCycles > PlsrFinalArmJobMaxCycles[owner])
    {
        PlsrFinalArmJobMaxCycles[owner] = elapsedCycles;
    }
#endif
    return 1U;
}

static void PlsrDispatchTimerIrq(uint8_t pulseOutput)
{
    if (PlsrFinalStopIrqIsPending(pulseOutput) != 0U)
    {
        PlsrHandleTimerIrq(pulseOutput);
        return;
    }
    if (PlsrHandleFinalArmJob(pulseOutput) != 0U)
    {
        return;
    }
    if (PlsrHandleScheduledAbVerify(pulseOutput) == 0U)
    {
        PlsrHandleTimerIrq(pulseOutput);
    }
}

void TIM1_UP_TIM10_IRQHandler(void)
{
    PlsrDispatchTimerIrq(0U);
}

void TIM8_UP_TIM13_IRQHandler(void)
{
    PlsrDispatchTimerIrq(1U);
}

void TIM1_TRG_COM_TIM11_IRQHandler(void)
{
    PlsrDispatchTimerIrq(2U);
}

void TIM8_TRG_COM_TIM14_IRQHandler(void)
{
    PlsrDispatchTimerIrq(3U);
}

static void PlsrHandleCounterIrq(uint8_t counterIndex)
{
    TIM_TypeDef *counter;
#if PLSR_DEBUG_TIMING
    uint32_t startedAt = DWT->CYCCNT;
#endif

    if (counterIndex >= PLSR_COUNTER_COUNT)
    {
        return;
    }
    counter = PlsrCounters[counterIndex];
    if (((counter->SR & TIM_SR_CC1IF) != 0UL)
        && ((counter->DIER & TIM_DIER_CC1IE) != 0UL))
    {
        uint8_t owner = PlsrCounterOwner[counterIndex];

        counter->SR = ~TIM_SR_CC1IF;
        if ((owner <= 3U) && (PlsrFiniteActive[owner] != 0U))
        {
            PlsrFinitePrepareNextStepIrq(owner, counter);
        }
    }
    if (((counter->SR & TIM_SR_UIF) != 0UL)
        && ((counter->DIER & TIM_DIER_UIE) != 0UL))
    {
        uint8_t owner = PlsrCounterOwner[counterIndex];

        counter->SR = ~TIM_SR_UIF;
        if ((owner <= 3U) && (PlsrFiniteActive[owner] != 0U))
        {
            PlsrFiniteCounterIrq(owner, counter);
#if PLSR_DEBUG_TIMING
            {
                uint32_t elapsedCycles = DWT->CYCCNT - startedAt;

                if (PlsrFiniteCompletionPending[owner] != 0U)
                {
                    PlsrFiniteFinalIrqLastCycles[owner] = elapsedCycles;
                    if (elapsedCycles > PlsrFiniteFinalIrqMaxCycles[owner])
                    {
                        PlsrFiniteFinalIrqMaxCycles[owner] = elapsedCycles;
                    }
                }
                else
                {
                    PlsrFiniteBlockIrqCount[owner]++;
                    if (elapsedCycles > PlsrFiniteBlockIrqMaxCycles[owner])
                    {
                        PlsrFiniteBlockIrqMaxCycles[owner] = elapsedCycles;
                    }
                }
            }
#endif
        }
        else
        {
            PlsrCounterOverflowPulses[counterIndex] +=
                PLSR_COUNTER_BLOCK_PULSES;
        }
    }
}

static void PlsrFiniteArmNextStepPrepare(uint8_t pulseOutput,
                                         TIM_TypeDef *counter,
                                         uint32_t blockPulses)
{
    uint16_t nextIndex =
        (uint16_t)(PlsrFiniteStepIndex[pulseOutput] + 1U);

    counter->DIER &= ~TIM_DIER_CC1IE;
    counter->SR = ~TIM_SR_CC1IF;
    if (PlsrFiniteRemainingPulses[pulseOutput] > blockPulses)
    {
        return;
    }
    if ((PlsrFiniteStreamActive[pulseOutput] == 0U)
        && (nextIndex >= PlsrFiniteStepCount[pulseOutput]))
    {
        return;
    }
    if (blockPulses > 1UL)
    {
        counter->CCR1 = blockPulses - 1UL;
        counter->DIER |= TIM_DIER_CC1IE;
    }
    else
    {
        PlsrFinitePrepareNextStepIrq(pulseOutput, counter);
    }
}

static void PlsrFinitePrepareNextStepIrq(uint8_t pulseOutput,
                                         TIM_TypeDef *counter)
{
    uint16_t nextIndex =
        (uint16_t)(PlsrFiniteStepIndex[pulseOutput] + 1U);
    TIM_TypeDef *timer;
    const PLSR_PLATFORM_TIMER_SETTING *next;

    counter->DIER &= ~TIM_DIER_CC1IE;
    if (PlsrFiniteStreamActive[pulseOutput] != 0U)
    {
        PLSR_PLATFORM_TIMER_SETTING streamSetting;
        uint32_t streamPulses = 0UL;
        uint8_t startsNextSegment = 0U;
        uint8_t takeResult;

        if ((PlsrFiniteStreamNextValid[pulseOutput] != 0U)
            || (PlsrFiniteStreamSourceDone[pulseOutput] != 0U)
            || (PlsrFiniteStreamSourceFault[pulseOutput] != 0U))
        {
            return;
        }
        takeResult = PlsrExecTakeCountedRunIrq(
            pulseOutput, &streamSetting, &streamPulses,
            &startsNextSegment);
        if (takeResult == PLSR_EXEC_RUN_DONE)
        {
            PlsrFiniteStreamSourceDone[pulseOutput] = 1U;
            return;
        }
        if ((takeResult != PLSR_EXEC_RUN_READY)
            || (streamPulses == 0UL)
            || (PlsrPreparedSettingIsValid(
                    pulseOutput, PLSR_OUTPUT_PULSE_DIR,
                    &streamSetting) == 0U))
        {
            PlsrFiniteStreamSourceFault[pulseOutput] = 1U;
            PlsrExecCountedStreamFaultIrq(pulseOutput);
            return;
        }
        timer = PlsrTimerMap[pulseOutput].timer;
        timer->PSC = streamSetting.prescaler;
        timer->ARR = streamSetting.period;
        timer->CCR1 = streamSetting.compare;
        PlsrTimerQueuedSetting[pulseOutput] = streamSetting;
        PlsrTimerQueuedFrequencyHz[pulseOutput] =
            streamSetting.actualFrequencyHz;
        PlsrFiniteStreamNextSetting[pulseOutput] = streamSetting;
        PlsrFiniteStreamNextPulses[pulseOutput] = streamPulses;
        PlsrFiniteStreamNextStartsSegment[pulseOutput] =
            startsNextSegment;
        PlsrFiniteStreamNextValid[pulseOutput] = 1U;
        return;
    }
    if (nextIndex >= PlsrFiniteStepCount[pulseOutput])
    {
        return;
    }
    timer = PlsrTimerMap[pulseOutput].timer;
    next = &PlsrFiniteSteps[pulseOutput][nextIndex].setting;
    timer->PSC = next->prescaler;
    timer->ARR = next->period;
    timer->CCR1 = next->compare;
    PlsrTimerQueuedSetting[pulseOutput] = *next;
    PlsrTimerQueuedFrequencyHz[pulseOutput] = next->actualFrequencyHz;
}

static void PlsrFiniteCounterIrq(uint8_t pulseOutput,
                                 TIM_TypeDef *counter)
{
    uint32_t completedBlock =
        (PlsrFiniteRemainingPulses[pulseOutput]
         > PLSR_COUNTER_BLOCK_PULSES)
            ? PLSR_COUNTER_BLOCK_PULSES
            : PlsrFiniteRemainingPulses[pulseOutput];

    PlsrFiniteRemainingPulses[pulseOutput] -= completedBlock;
    if (PlsrFiniteRemainingPulses[pulseOutput] != 0UL)
    {
        uint32_t nextBlock =
            (PlsrFiniteRemainingPulses[pulseOutput]
             > PLSR_COUNTER_BLOCK_PULSES)
                ? PLSR_COUNTER_BLOCK_PULSES
                : PlsrFiniteRemainingPulses[pulseOutput];

        PlsrCounterOverflowPulses[PlsrCounterIndexByOutput[pulseOutput]] +=
            completedBlock;
        counter->ARR = (nextBlock == 1UL) ? 1UL : (nextBlock - 1UL);
        PlsrFiniteCounterPreload[pulseOutput] =
            (nextBlock == 1UL) ? 1U : 0U;
        counter->CNT = PlsrFiniteCounterPreload[pulseOutput];
        PlsrFiniteArmNextStepPrepare(pulseOutput, counter, nextBlock);
        return;
    }

    if (PlsrFiniteStreamActive[pulseOutput] != 0U)
    {
        PlsrObservedPulseBase[pulseOutput] +=
            PlsrFiniteTargetPulses[pulseOutput];
        PlsrObservedPulsePublished[pulseOutput] =
            PlsrObservedPulseBase[pulseOutput];
        if (PlsrFiniteStreamNextValid[pulseOutput] != 0U)
        {
            uint32_t nextPulses =
                PlsrFiniteStreamNextPulses[pulseOutput];
            uint32_t firstBlock =
                (nextPulses > PLSR_COUNTER_BLOCK_PULSES)
                    ? PLSR_COUNTER_BLOCK_PULSES : nextPulses;

            if (PlsrFiniteStreamNextStartsSegment[pulseOutput] != 0U)
            {
                /* 段边界回调只传"到当前 run 完成为止的累计计数"（IRQ 内
                   已累加完成的 base），执行器只置事件，不做簿记。 */
                PlsrExecCountedSegmentBoundaryIrq(
                    pulseOutput, PlsrObservedPulseBase[pulseOutput]);
            }
            PlsrFiniteTargetPulses[pulseOutput] = nextPulses;
            PlsrFiniteRemainingPulses[pulseOutput] = nextPulses;
            PlsrCounterOverflowPulses[
                PlsrCounterIndexByOutput[pulseOutput]] = 0UL;
            counter->ARR = (firstBlock == 1UL)
                               ? 1UL : (firstBlock - 1UL);
            PlsrFiniteCounterPreload[pulseOutput] =
                (firstBlock == 1UL) ? 1U : 0U;
            counter->CNT = PlsrFiniteCounterPreload[pulseOutput];
            PlsrTimerActiveSetting[pulseOutput] =
                PlsrFiniteStreamNextSetting[pulseOutput];
            PlsrTimerActiveFrequencyHz[pulseOutput] =
                PlsrFiniteStreamNextSetting[pulseOutput].actualFrequencyHz;
            PlsrFiniteStreamNextValid[pulseOutput] = 0U;
            PlsrFiniteStreamNextStartsSegment[pulseOutput] = 0U;
            PlsrFiniteArmNextStepPrepare(pulseOutput, counter, firstBlock);
            return;
        }
    }
    else if (PlsrFiniteStepCount[pulseOutput] != 0U)
    {
        uint16_t completedIndex = PlsrFiniteStepIndex[pulseOutput];
        uint16_t nextIndex = (uint16_t)(completedIndex + 1U);
        uint8_t hasNext = (nextIndex
                           < PlsrFiniteStepCount[pulseOutput]) ? 1U : 0U;

        PlsrObservedPulseBase[pulseOutput] +=
            PlsrFiniteTargetPulses[pulseOutput];
        PlsrObservedPulsePublished[pulseOutput] =
            PlsrObservedPulseBase[pulseOutput];
        PlsrFiniteCompletedStepCount[pulseOutput] =
            (uint16_t)(completedIndex + 1U);

        if (hasNext != 0U)
        {
            const PLSR_PLATFORM_FINITE_STEP *next =
                &PlsrFiniteSteps[pulseOutput][nextIndex];
            uint32_t firstBlock =
                (next->pulseCount > PLSR_COUNTER_BLOCK_PULSES)
                    ? PLSR_COUNTER_BLOCK_PULSES : next->pulseCount;
            PlsrFiniteStepIndex[pulseOutput] = nextIndex;
            PlsrFiniteTargetPulses[pulseOutput] = next->pulseCount;
            PlsrFiniteRemainingPulses[pulseOutput] = next->pulseCount;
            PlsrCounterOverflowPulses[
                PlsrCounterIndexByOutput[pulseOutput]] = 0UL;
            counter->ARR = (firstBlock == 1UL)
                               ? 1UL : (firstBlock - 1UL);
            PlsrFiniteCounterPreload[pulseOutput] =
                (firstBlock == 1UL) ? 1U : 0U;
            counter->CNT = PlsrFiniteCounterPreload[pulseOutput];
            PlsrTimerActiveSetting[pulseOutput] = next->setting;
            PlsrTimerActiveFrequencyHz[pulseOutput] =
                next->setting.actualFrequencyHz;
            PlsrTimerQueuedSetting[pulseOutput] = next->setting;
            PlsrTimerQueuedFrequencyHz[pulseOutput] =
                next->setting.actualFrequencyHz;
            PlsrFiniteArmNextStepPrepare(pulseOutput, counter, firstBlock);
            return;
        }
    }

    counter->DIER = 0UL;
    counter->CR1 &= ~TIM_CR1_CEN;
    counter->SMCR &= ~(TIM_SMCR_SMS_2 | TIM_SMCR_SMS_1 | TIM_SMCR_SMS_0);

    /*
     * An OC rising edge is the terminal pulse's falling edge because the
     * output stage is active low.  The target-count update IRQ therefore is
     * already the safe idle boundary: stop here before CCR1 can start an
     * extra terminal pulse.
     */
    PlsrFiniteStopAtFallingEdge(pulseOutput);
}

static void PlsrFiniteRetargetAtFallingEdge(uint8_t pulseOutput)
{
    uint8_t counterIndex = PlsrCounterIndexByOutput[pulseOutput];
    TIM_TypeDef *counter = PlsrCounters[counterIndex];
    TIM_TypeDef *timer = PlsrTimerMap[pulseOutput].timer;
    uint32_t drainPulses = PlsrFiniteRetargetDrainPulses[pulseOutput];
    uint32_t blockCount;
    uint32_t completed;

    PlsrFiniteRetargetPending[pulseOutput] = 0U;
    PlsrFiniteRetargetDrainPulses[pulseOutput] = 0UL;
    timer->DIER &= ~TIM_DIER_CC1IE;
    PlsrCounterSuspend(pulseOutput);
    blockCount = (uint16_t)counter->CNT;
    if (blockCount >= PlsrFiniteCounterPreload[pulseOutput])
    {
        blockCount -= PlsrFiniteCounterPreload[pulseOutput];
    }
    completed = PlsrFiniteTargetPulses[pulseOutput]
                - PlsrFiniteRemainingPulses[pulseOutput] + blockCount;
    if (PlsrFiniteStepCount[pulseOutput] != 0U)
    {
        completed += PlsrFiniteSteps[pulseOutput][
            PlsrFiniteStepIndex[pulseOutput]].segmentPulseOffset;
    }
    if (completed > PlsrFiniteTargetPulses[pulseOutput])
    {
        completed = PlsrFiniteTargetPulses[pulseOutput];
    }
    PlsrFiniteTargetPulses[pulseOutput] = completed + drainPulses;
    PlsrFiniteRemainingPulses[pulseOutput] = drainPulses;
    PlsrFiniteStepCount[pulseOutput] = 0U;
    PlsrFiniteStepIndex[pulseOutput] = 0U;
    PlsrFiniteBoundaryReadIndex[pulseOutput] = 0U;
    PlsrFiniteCompletedStepCount[pulseOutput] = 0U;
    counter->ARR = (drainPulses == 1UL) ? 1UL : (drainPulses - 1UL);
    PlsrFiniteCounterPreload[pulseOutput] =
        (drainPulses == 1UL) ? 1U : 0U;
    counter->CNT = 0UL;
    counter->EGR = TIM_EGR_UG;
    counter->CNT = PlsrFiniteCounterPreload[pulseOutput];
    counter->SR = 0UL;
    counter->DIER = TIM_DIER_UIE;
    PlsrCounterBegin(pulseOutput);
}

static void PlsrFiniteStopAtFallingEdge(uint8_t pulseOutput)
{
    TIM_TypeDef *timer = PlsrTimerMap[pulseOutput].timer;

    /* OC1 and GPIO idle are both high here; hand off without a pin glitch. */
    PlsrPulsePinCaptureIdle(pulseOutput);
    timer->DIER = 0UL;
    timer->CCER &= ~(TIM_CCER_CC1E | TIM_CCER_CC1P);
    timer->CR1 &= ~TIM_CR1_CEN;
    timer->SR = ~(TIM_SR_UIF | TIM_SR_CC1IF);
    PlsrFiniteTailStopPending[pulseOutput] = 0U;
    PlsrFiniteActive[pulseOutput] = 0U;
    PlsrFiniteCompletionPending[pulseOutput] = 1U;
    PlsrFiniteFrequencyPending[pulseOutput] = 0U;
    PlsrFiniteCounterPreload[pulseOutput] = 0U;
    __DSB();
}

void TIM1_BRK_TIM9_IRQHandler(void)
{
    PlsrHandleCounterIrq(0U);
}

void TIM8_BRK_TIM12_IRQHandler(void)
{
    PlsrHandleCounterIrq(1U);
}

#endif /* PLSR_HOST_TEST */