diff --git a/cores/esp8266/Tone.cpp b/cores/esp8266/Tone.cpp index 064fdad5d..601b1df51 100644 --- a/cores/esp8266/Tone.cpp +++ b/cores/esp8266/Tone.cpp @@ -25,10 +25,6 @@ #include "core_esp8266_waveform.h" #include "user_interface.h" -// Which pins have a tone running on them? -static uint32_t _toneMap = 0; - - static void _startTone(uint8_t _pin, uint32_t high, uint32_t low, uint32_t duration) { if (_pin > 16) { return; @@ -42,9 +38,7 @@ static void _startTone(uint8_t _pin, uint32_t high, uint32_t low, uint32_t durat duration = microsecondsToClockCycles(duration * 1000UL); duration += high + low - 1; duration -= duration % (high + low); - if (startWaveformClockCycles(_pin, high, low, duration)) { - _toneMap |= 1 << _pin; - } + startWaveformClockCycles(_pin, high, low, duration); } @@ -86,6 +80,5 @@ void noTone(uint8_t _pin) { return; } stopWaveform(_pin); - _toneMap &= ~(1 << _pin); digitalWrite(_pin, 0); } diff --git a/cores/esp8266/core_esp8266_waveform.cpp b/cores/esp8266/core_esp8266_waveform.cpp index 597a8e88a..952e1fd19 100644 --- a/cores/esp8266/core_esp8266_waveform.cpp +++ b/cores/esp8266/core_esp8266_waveform.cpp @@ -3,6 +3,7 @@ supporting outputs on all pins in parallel. Copyright (c) 2018 Earle F. Philhower, III. All rights reserved. + Copyright (c) 2020 Dirk O. Kaar. The core idea is to have a programmable waveform generator with a unique high and low period (defined in microseconds or CPU clock cycles). TIMER1 is @@ -19,8 +20,8 @@ This replaces older tone(), analogWrite(), and the Servo classes. - Everywhere in the code where "cycles" is used, it means ESP.getCycleCount() - clock cycle count, or an interval measured in CPU clock cycles, but not TIMER1 + Everywhere in the code where "ccy" or "ccys" is used, it means ESP.getCycleCount() + clock cycle time, or an interval measured in clock cycles, but not TIMER1 cycles (which may be 2 CPU clock cycles @ 160MHz). This library is free software; you can redistribute it and/or @@ -38,275 +39,398 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ +#include "core_esp8266_waveform.h" #include #include "ets_sys.h" -#include "core_esp8266_waveform.h" +#include -extern "C" { +// Timer is 80MHz fixed. 160MHz CPU frequency need scaling. +constexpr bool ISCPUFREQ160MHZ = clockCyclesPerMicrosecond() == 160; +// Maximum delay between IRQs, Timer1, <= 2^23 / 80MHz +constexpr int32_t MAXIRQTICKSCCYS = microsecondsToClockCycles(10000); +// Maximum servicing time for any single IRQ +constexpr uint32_t ISRTIMEOUTCCYS = microsecondsToClockCycles(18); +// The latency between in-ISR rearming of the timer and the earliest firing +constexpr int32_t IRQLATENCYCCYS = microsecondsToClockCycles(2); +// The SDK and hardware take some time to actually get to our NMI code +constexpr int32_t DELTAIRQCCYS = ISCPUFREQ160MHZ ? + microsecondsToClockCycles(2) >> 1 : microsecondsToClockCycles(2); -// Maximum delay between IRQs -#define MAXIRQUS (10000) - -// Set/clear GPIO 0-15 by bitmask -#define SetGPIO(a) do { GPOS = a; } while (0) -#define ClearGPIO(a) do { GPOC = a; } while (0) +// for INFINITE, the NMI proceeds on the waveform without expiry deadline. +// for EXPIRES, the NMI expires the waveform automatically on the expiry ccy. +// for UPDATEEXPIRY, the NMI recomputes the exact expiry ccy and transitions to EXPIRES. +// for INIT, the NMI initializes nextPeriodCcy, and if expiryCcy != 0 includes UPDATEEXPIRY. +enum class WaveformMode : uint8_t {INFINITE = 0, EXPIRES = 1, UPDATEEXPIRY = 2, INIT = 3}; // Waveform generator can create tones, PWM, and servos typedef struct { - uint32_t nextServiceCycle; // ESP cycle timer when a transition required - uint32_t expiryCycle; // For time-limited waveform, the cycle when this waveform must stop - uint32_t nextTimeHighCycles; // Copy over low->high to keep smooth waveform - uint32_t nextTimeLowCycles; // Copy over high->low to keep smooth waveform + uint32_t nextPeriodCcy; // ESP clock cycle when a period begins. If WaveformMode::INIT, temporarily holds positive phase offset ccy count + uint32_t endDutyCcy; // ESP clock cycle when going from duty to off + int32_t dutyCcys; // Set next off cycle at low->high to maintain phase + int32_t adjDutyCcys; // Temporary correction for next period + int32_t periodCcys; // Set next phase cycle at low->high to maintain phase + uint32_t expiryCcy; // For time-limited waveform, the CPU clock cycle when this waveform must stop. If WaveformMode::UPDATE, temporarily holds relative ccy count + WaveformMode mode; + int8_t alignPhase; // < 0 no phase alignment, otherwise starts waveform in relative phase offset to given pin + bool autoPwm; // perform PWM duty to idle cycle ratio correction under high load at the expense of precise timings } Waveform; -static Waveform waveform[17]; // State of all possible pins -static volatile uint32_t waveformState = 0; // Is the pin high or low, updated in NMI so no access outside the NMI code -static volatile uint32_t waveformEnabled = 0; // Is it actively running, updated in NMI so no access outside the NMI code +namespace { -// Enable lock-free by only allowing updates to waveformState and waveformEnabled from IRQ service routine -static volatile uint32_t waveformToEnable = 0; // Message to the NMI handler to start a waveform on a inactive pin -static volatile uint32_t waveformToDisable = 0; // Message to the NMI handler to disable a pin from waveform generation + static struct { + Waveform pins[17]; // State of all possible pins + uint32_t states = 0; // Is the pin high or low, updated in NMI so no access outside the NMI code + uint32_t enabled = 0; // Is it actively running, updated in NMI so no access outside the NMI code -static uint32_t (*timer1CB)() = NULL; + // Enable lock-free by only allowing updates to waveform.states and waveform.enabled from IRQ service routine + int32_t toSetBits = 0; // Message to the NMI handler to start/modify exactly one waveform + int32_t toDisableBits = 0; // Message to the NMI handler to disable exactly one pin from waveform generation + uint32_t(*timer1CB)() = nullptr; -// Non-speed critical bits -#pragma GCC optimize ("Os") + bool timer1Running = false; + + uint32_t nextEventCcy; + } waveform; -static inline ICACHE_RAM_ATTR uint32_t GetCycleCount() { - uint32_t ccount; - __asm__ __volatile__("esync; rsr %0,ccount":"=a"(ccount)); - return ccount; } // Interrupt on/off control static ICACHE_RAM_ATTR void timer1Interrupt(); -static bool timerRunning = false; + +// Non-speed critical bits +#pragma GCC optimize ("Os") static void initTimer() { timer1_disable(); ETS_FRC_TIMER1_INTR_ATTACH(NULL, NULL); ETS_FRC_TIMER1_NMI_INTR_ATTACH(timer1Interrupt); timer1_enable(TIM_DIV1, TIM_EDGE, TIM_SINGLE); - timerRunning = true; + waveform.timer1Running = true; + timer1_write(IRQLATENCYCCYS); // Cause an interrupt post-haste } static void ICACHE_RAM_ATTR deinitTimer() { ETS_FRC_TIMER1_NMI_INTR_ATTACH(NULL); timer1_disable(); timer1_isr_init(); - timerRunning = false; + waveform.timer1Running = false; } +extern "C" { + // Set a callback. Pass in NULL to stop it void setTimer1Callback(uint32_t (*fn)()) { - timer1CB = fn; - if (!timerRunning && fn) { + waveform.timer1CB = fn; + std::atomic_thread_fence(std::memory_order_acq_rel); + if (!waveform.timer1Running && fn) { initTimer(); - timer1_write(microsecondsToClockCycles(1)); // Cause an interrupt post-haste - } else if (timerRunning && !fn && !waveformEnabled) { + } else if (waveform.timer1Running && !fn && !waveform.enabled) { deinitTimer(); } } +int startWaveform(uint8_t pin, uint32_t highUS, uint32_t lowUS, + uint32_t runTimeUS, int8_t alignPhase, uint32_t phaseOffsetUS, bool autoPwm) { + return startWaveformClockCycles(pin, + microsecondsToClockCycles(highUS), microsecondsToClockCycles(lowUS), + microsecondsToClockCycles(runTimeUS), alignPhase, microsecondsToClockCycles(phaseOffsetUS), autoPwm); +} + // Start up a waveform on a pin, or change the current one. Will change to the new // waveform smoothly on next low->high transition. For immediate change, stopWaveform() // first, then it will immediately begin. -int startWaveform(uint8_t pin, uint32_t timeHighUS, uint32_t timeLowUS, uint32_t runTimeUS) { - return startWaveformClockCycles(pin, microsecondsToClockCycles(timeHighUS), microsecondsToClockCycles(timeLowUS), microsecondsToClockCycles(runTimeUS)); -} - -int startWaveformClockCycles(uint8_t pin, uint32_t timeHighCycles, uint32_t timeLowCycles, uint32_t runTimeCycles) { - if ((pin > 16) || isFlashInterfacePin(pin)) { +int startWaveformClockCycles(uint8_t pin, uint32_t highCcys, uint32_t lowCcys, + uint32_t runTimeCcys, int8_t alignPhase, uint32_t phaseOffsetCcys, bool autoPwm) { + uint32_t periodCcys = highCcys + lowCcys; + if (periodCcys < MAXIRQTICKSCCYS) { + if (!highCcys) { + periodCcys = (MAXIRQTICKSCCYS / periodCcys) * periodCcys; + } + else if (!lowCcys) { + highCcys = periodCcys = (MAXIRQTICKSCCYS / periodCcys) * periodCcys; + } + } + // sanity checks, including mixed signed/unsigned arithmetic safety + if ((pin > 16) || isFlashInterfacePin(pin) || (alignPhase > 16) || + static_cast(periodCcys) <= 0 || + static_cast(highCcys) < 0 || static_cast(lowCcys) < 0) { return false; } - Waveform *wave = &waveform[pin]; - // Adjust to shave off some of the IRQ time, approximately - wave->nextTimeHighCycles = timeHighCycles; - wave->nextTimeLowCycles = timeLowCycles; - wave->expiryCycle = runTimeCycles ? GetCycleCount() + runTimeCycles : 0; - if (runTimeCycles && !wave->expiryCycle) { - wave->expiryCycle = 1; // expiryCycle==0 means no timeout, so avoid setting it - } + Waveform& wave = waveform.pins[pin]; + wave.dutyCcys = highCcys; + wave.adjDutyCcys = 0; + wave.periodCcys = periodCcys; + wave.autoPwm = autoPwm; - uint32_t mask = 1<nextServiceCycle = GetCycleCount() + microsecondsToClockCycles(1); - waveformToEnable |= mask; - if (!timerRunning) { - initTimer(); - timer1_write(microsecondsToClockCycles(10)); - } else { - // Ensure timely service.... - if (T1L > microsecondsToClockCycles(10)) { - timer1_write(microsecondsToClockCycles(10)); + std::atomic_thread_fence(std::memory_order_acquire); + const uint32_t pinBit = 1UL << pin; + if (!(waveform.enabled & pinBit)) { + // wave.nextPeriodCcy and wave.endDutyCcy are initialized by the ISR + wave.nextPeriodCcy = phaseOffsetCcys; + wave.expiryCcy = runTimeCcys; // in WaveformMode::INIT, temporarily hold relative cycle count + wave.mode = WaveformMode::INIT; + wave.alignPhase = (alignPhase < 0) ? -1 : alignPhase; + if (!wave.dutyCcys) { + // If initially at zero duty cycle, force GPIO off + if (pin == 16) { + GP16O = 0; + } + else { + GPOC = pinBit; } } - while (waveformToEnable) { - delay(0); // Wait for waveform to update + std::atomic_thread_fence(std::memory_order_release); + waveform.toSetBits = 1UL << pin; + std::atomic_thread_fence(std::memory_order_release); + if (!waveform.timer1Running) { + initTimer(); + } + else if (T1V > IRQLATENCYCCYS) { + // Must not interfere if Timer is due shortly + timer1_write(IRQLATENCYCCYS); } } - - return true; -} - -// Speed critical bits -#pragma GCC optimize ("O2") -// Normally would not want two copies like this, but due to different -// optimization levels the inline attribute gets lost if we try the -// other version. - -static inline ICACHE_RAM_ATTR uint32_t GetCycleCountIRQ() { - uint32_t ccount; - __asm__ __volatile__("rsr %0,ccount":"=a"(ccount)); - return ccount; -} - -static inline ICACHE_RAM_ATTR uint32_t min_u32(uint32_t a, uint32_t b) { - if (a < b) { - return a; + else { + wave.mode = WaveformMode::INFINITE; // turn off possible expiry to make update atomic from NMI + std::atomic_thread_fence(std::memory_order_release); + wave.expiryCcy = runTimeCcys; // in WaveformMode::UPDATEEXPIRY, temporarily hold relative cycle count + if (runTimeCcys) { + wave.mode = WaveformMode::UPDATEEXPIRY; + std::atomic_thread_fence(std::memory_order_release); + waveform.toSetBits = 1UL << pin; + } } - return b; + std::atomic_thread_fence(std::memory_order_acq_rel); + while (waveform.toSetBits) { + delay(0); // Wait for waveform to update + std::atomic_thread_fence(std::memory_order_acquire); + } + return true; } // Stops a waveform on a pin int ICACHE_RAM_ATTR stopWaveform(uint8_t pin) { // Can't possibly need to stop anything if there is no timer active - if (!timerRunning) { + if (!waveform.timer1Running) { return false; } // If user sends in a pin >16 but <32, this will always point to a 0 bit // If they send >=32, then the shift will result in 0 and it will also return false - if (waveformEnabled & (1UL << pin)) { - waveformToDisable = 1UL << pin; + std::atomic_thread_fence(std::memory_order_acquire); + const uint32_t pinBit = 1UL << pin; + if (waveform.enabled & pinBit) { + waveform.toDisableBits = 1UL << pin; + std::atomic_thread_fence(std::memory_order_release); // Must not interfere if Timer is due shortly - if (T1L > microsecondsToClockCycles(10)) { - timer1_write(microsecondsToClockCycles(10)); + if (T1V > IRQLATENCYCCYS) { + timer1_write(IRQLATENCYCCYS); } - while (waveformToDisable) { + while (waveform.toDisableBits) { /* no-op */ // Can't delay() since stopWaveform may be called from an IRQ + std::atomic_thread_fence(std::memory_order_acquire); } } - if (!waveformEnabled && !timer1CB) { + if (!waveform.enabled && !waveform.timer1CB) { deinitTimer(); } return true; } -// The SDK and hardware take some time to actually get to our NMI code, so -// decrement the next IRQ's timer value by a bit so we can actually catch the -// real CPU cycle counter we want for the waveforms. -#if F_CPU == 80000000 - #define DELTAIRQ (microsecondsToClockCycles(3)) -#else - #define DELTAIRQ (microsecondsToClockCycles(2)) -#endif +}; +// Speed critical bits +#pragma GCC optimize ("O2") -static ICACHE_RAM_ATTR void timer1Interrupt() { - // Optimize the NMI inner loop by keeping track of the min and max GPIO that we - // are generating. In the common case (1 PWM) these may be the same pin and - // we can avoid looking at the other pins. - static int startPin = 0; - static int endPin = 0; - - uint32_t nextEventCycles = microsecondsToClockCycles(MAXIRQUS); - uint32_t timeoutCycle = GetCycleCountIRQ() + microsecondsToClockCycles(14); - - if (waveformToEnable || waveformToDisable) { - // Handle enable/disable requests from main app. - waveformEnabled = (waveformEnabled & ~waveformToDisable) | waveformToEnable; // Set the requested waveforms on/off - waveformState &= ~waveformToEnable; // And clear the state of any just started - waveformToEnable = 0; - waveformToDisable = 0; - // Find the first GPIO being generated by checking GCC's find-first-set (returns 1 + the bit of the first 1 in an int32_t) - startPin = __builtin_ffs(waveformEnabled) - 1; - // Find the last bit by subtracting off GCC's count-leading-zeros (no offset in this one) - endPin = 32 - __builtin_clz(waveformEnabled); +// For dynamic CPU clock frequency switch in loop the scaling logic would have to be adapted. +// Using constexpr makes sure that the CPU clock frequency is compile-time fixed. +static inline ICACHE_RAM_ATTR int32_t scaleCcys(const int32_t ccys, const bool isCPU2X) { + if (ISCPUFREQ160MHZ) { + return isCPU2X ? ccys : (ccys >> 1); } - - bool done = false; - if (waveformEnabled) { - do { - nextEventCycles = microsecondsToClockCycles(MAXIRQUS); - for (int i = startPin; i <= endPin; i++) { - uint32_t mask = 1<expiryCycle) { - int32_t expiryToGo = wave->expiryCycle - now; - if (expiryToGo < 0) { - // Done, remove! - waveformEnabled &= ~mask; - if (i == 16) { - GP16O &= ~1; - } else { - ClearGPIO(mask); - } - continue; - } - } - - // Check for toggles - int32_t cyclesToGo = wave->nextServiceCycle - now; - if (cyclesToGo < 0) { - waveformState ^= mask; - if (waveformState & mask) { - if (i == 16) { - GP16O |= 1; // GPIO16 write slow as it's RMW - } else { - SetGPIO(mask); - } - wave->nextServiceCycle = now + wave->nextTimeHighCycles; - nextEventCycles = min_u32(nextEventCycles, wave->nextTimeHighCycles); - } else { - if (i == 16) { - GP16O &= ~1; // GPIO16 write slow as it's RMW - } else { - ClearGPIO(mask); - } - wave->nextServiceCycle = now + wave->nextTimeLowCycles; - nextEventCycles = min_u32(nextEventCycles, wave->nextTimeLowCycles); - } - } else { - uint32_t deltaCycles = wave->nextServiceCycle - now; - nextEventCycles = min_u32(nextEventCycles, deltaCycles); - } - } - - // Exit the loop if we've hit the fixed runtime limit or the next event is known to be after that timeout would occur - uint32_t now = GetCycleCountIRQ(); - int32_t cycleDeltaNextEvent = timeoutCycle - (now + nextEventCycles); - int32_t cyclesLeftTimeout = timeoutCycle - now; - done = (cycleDeltaNextEvent < 0) || (cyclesLeftTimeout < 0); - } while (!done); - } // if (waveformEnabled) - - if (timer1CB) { - nextEventCycles = min_u32(nextEventCycles, timer1CB()); + else { + return isCPU2X ? (ccys << 1) : ccys; } - - if (nextEventCycles < microsecondsToClockCycles(10)) { - nextEventCycles = microsecondsToClockCycles(10); - } - nextEventCycles -= DELTAIRQ; - - // Do it here instead of global function to save time and because we know it's edge-IRQ -#if F_CPU == 160000000 - T1L = nextEventCycles >> 1; // Already know we're in range by MAXIRQUS -#else - T1L = nextEventCycles; // Already know we're in range by MAXIRQUS -#endif - TEIE |= TEIE1; // Edge int enable } -}; +static ICACHE_RAM_ATTR void timer1Interrupt() { + const uint32_t isrStartCcy = ESP.getCycleCount(); + int32_t clockDrift = isrStartCcy - waveform.nextEventCcy; + const bool isCPU2X = CPU2X & 1; + if ((waveform.toSetBits && !(waveform.enabled & waveform.toSetBits)) || waveform.toDisableBits) { + // Handle enable/disable requests from main app. + waveform.enabled = (waveform.enabled & ~waveform.toDisableBits) | waveform.toSetBits; // Set the requested waveforms on/off + // Find the first GPIO being generated by checking GCC's find-first-set (returns 1 + the bit of the first 1 in an int32_t) + waveform.toDisableBits = 0; + } + + if (waveform.toSetBits) { + const int toSetPin = __builtin_ffs(waveform.toSetBits) - 1; + Waveform& wave = waveform.pins[toSetPin]; + switch (wave.mode) { + case WaveformMode::INIT: + waveform.states &= ~waveform.toSetBits; // Clear the state of any just started + if (wave.alignPhase >= 0 && waveform.enabled & (1UL << wave.alignPhase)) { + wave.nextPeriodCcy = waveform.pins[wave.alignPhase].nextPeriodCcy + wave.nextPeriodCcy; + } + else { + wave.nextPeriodCcy = waveform.nextEventCcy; + } + if (!wave.expiryCcy) { + wave.mode = WaveformMode::INFINITE; + break; + } + // fall through + case WaveformMode::UPDATEEXPIRY: + // in WaveformMode::UPDATEEXPIRY, expiryCcy temporarily holds relative CPU cycle count + wave.expiryCcy = wave.nextPeriodCcy + scaleCcys(wave.expiryCcy, isCPU2X); + wave.mode = WaveformMode::EXPIRES; + break; + default: + break; + } + waveform.toSetBits = 0; + } + + // Exit the loop if the next event, if any, is sufficiently distant. + const uint32_t isrTimeoutCcy = isrStartCcy + ISRTIMEOUTCCYS; + uint32_t busyPins = waveform.enabled; + waveform.nextEventCcy = isrStartCcy + MAXIRQTICKSCCYS; + + uint32_t now = ESP.getCycleCount(); + uint32_t isrNextEventCcy = now; + while (busyPins) { + if (static_cast(isrNextEventCcy - now) > IRQLATENCYCCYS) { + waveform.nextEventCcy = isrNextEventCcy; + break; + } + isrNextEventCcy = waveform.nextEventCcy; + uint32_t loopPins = busyPins; + while (loopPins) { + const int pin = __builtin_ffsl(loopPins) - 1; + const uint32_t pinBit = 1UL << pin; + loopPins ^= pinBit; + + Waveform& wave = waveform.pins[pin]; + + if (clockDrift) { + wave.endDutyCcy += clockDrift; + wave.nextPeriodCcy += clockDrift; + wave.expiryCcy += clockDrift; + } + + uint32_t waveNextEventCcy = (waveform.states & pinBit) ? wave.endDutyCcy : wave.nextPeriodCcy; + if (WaveformMode::EXPIRES == wave.mode && + static_cast(waveNextEventCcy - wave.expiryCcy) >= 0 && + static_cast(now - wave.expiryCcy) >= 0) { + // Disable any waveforms that are done + waveform.enabled ^= pinBit; + busyPins ^= pinBit; + } + else { + const int32_t overshootCcys = now - waveNextEventCcy; + if (overshootCcys >= 0) { + const int32_t periodCcys = scaleCcys(wave.periodCcys, isCPU2X); + if (waveform.states & pinBit) { + // active configuration and forward are 100% duty + if (wave.periodCcys == wave.dutyCcys) { + wave.nextPeriodCcy += periodCcys; + wave.endDutyCcy = wave.nextPeriodCcy; + } + else { + if (wave.autoPwm) { + wave.adjDutyCcys += overshootCcys; + } + waveform.states ^= pinBit; + if (16 == pin) { + GP16O = 0; + } + else { + GPOC = pinBit; + } + } + waveNextEventCcy = wave.nextPeriodCcy; + } + else { + wave.nextPeriodCcy += periodCcys; + if (!wave.dutyCcys) { + wave.endDutyCcy = wave.nextPeriodCcy; + } + else { + int32_t dutyCcys = scaleCcys(wave.dutyCcys, isCPU2X); + if (dutyCcys <= wave.adjDutyCcys) { + dutyCcys >>= 1; + wave.adjDutyCcys -= dutyCcys; + } + else if (wave.adjDutyCcys) { + dutyCcys -= wave.adjDutyCcys; + wave.adjDutyCcys = 0; + } + wave.endDutyCcy = now + dutyCcys; + if (static_cast(wave.endDutyCcy - wave.nextPeriodCcy) > 0) { + wave.endDutyCcy = wave.nextPeriodCcy; + } + waveform.states |= pinBit; + if (16 == pin) { + GP16O = 1; + } + else { + GPOS = pinBit; + } + } + waveNextEventCcy = wave.endDutyCcy; + } + + if (WaveformMode::EXPIRES == wave.mode && static_cast(waveNextEventCcy - wave.expiryCcy) > 0) { + waveNextEventCcy = wave.expiryCcy; + } + } + + if (static_cast(waveNextEventCcy - isrTimeoutCcy) >= 0) { + busyPins ^= pinBit; + if (static_cast(waveform.nextEventCcy - waveNextEventCcy) > 0) { + waveform.nextEventCcy = waveNextEventCcy; + } + } + else if (static_cast(isrNextEventCcy - waveNextEventCcy) > 0) { + isrNextEventCcy = waveNextEventCcy; + } + } + now = ESP.getCycleCount(); + } + clockDrift = 0; + } + + int32_t callbackCcys = 0; + if (waveform.timer1CB) { + callbackCcys = scaleCcys(microsecondsToClockCycles(waveform.timer1CB()), isCPU2X); + } + now = ESP.getCycleCount(); + int32_t nextEventCcys = waveform.nextEventCcy - now; + // Account for unknown duration of timer1CB(). + if (waveform.timer1CB && nextEventCcys > callbackCcys) { + waveform.nextEventCcy = now + callbackCcys; + nextEventCcys = callbackCcys; + } + + // Timer is 80MHz fixed. 160MHz CPU frequency need scaling. + int32_t deltaIrqCcys = DELTAIRQCCYS; + int32_t irqLatencyCcys = IRQLATENCYCCYS; + if (isCPU2X) { + nextEventCcys >>= 1; + deltaIrqCcys >>= 1; + irqLatencyCcys >>= 1; + } + + // Firing timer too soon, the NMI occurs before ISR has returned. + if (nextEventCcys < irqLatencyCcys + deltaIrqCcys) { + waveform.nextEventCcy = now + IRQLATENCYCCYS + DELTAIRQCCYS; + nextEventCcys = irqLatencyCcys; + } + else { + nextEventCcys -= deltaIrqCcys; + } + + // Register access is fast and edge IRQ was configured before. + T1L = nextEventCcys; +} diff --git a/cores/esp8266/core_esp8266_waveform.h b/cores/esp8266/core_esp8266_waveform.h index e42a17f89..61cb99966 100644 --- a/cores/esp8266/core_esp8266_waveform.h +++ b/cores/esp8266/core_esp8266_waveform.h @@ -3,6 +3,7 @@ supporting outputs on all pins in parallel. Copyright (c) 2018 Earle F. Philhower, III. All rights reserved. + Copyright (c) 2020 Dirk O. Kaar. The core idea is to have a programmable waveform generator with a unique high and low period (defined in microseconds or CPU clock cycles). TIMER1 is @@ -19,7 +20,7 @@ This replaces older tone(), analogWrite(), and the Servo classes. - Everywhere in the code where "cycles" is used, it means ESP.getCycleCount() + Everywhere in the code where "ccy" or "ccys" is used, it means ESP.getCycleCount() clock cycle count, or an interval measured in CPU clock cycles, but not TIMER1 cycles (which may be 2 CPU clock cycles @ 160MHz). @@ -48,13 +49,25 @@ extern "C" { #endif // Start or change a waveform of the specified high and low times on specific pin. -// If runtimeUS > 0 then automatically stop it after that many usecs. +// If runtimeUS > 0 then automatically stop it after that many usecs, relative to the next +// full period. +// If waveform is not yet started on pin, and on pin == alignPhase a waveform is running, +// the new waveform is started at phaseOffsetUS phase offset, in microseconds, to that. +// Setting autoPwm to true allows the wave generator to maintain PWM duty to idle cycle ratio +// under load, for applications where frequency or duty cycle must not change, leave false. // Returns true or false on success or failure. -int startWaveform(uint8_t pin, uint32_t timeHighUS, uint32_t timeLowUS, uint32_t runTimeUS); +int startWaveform(uint8_t pin, uint32_t timeHighUS, uint32_t timeLowUS, + uint32_t runTimeUS = 0, int8_t alignPhase = -1, uint32_t phaseOffsetUS = 0, bool autoPwm = false); // Start or change a waveform of the specified high and low CPU clock cycles on specific pin. -// If runtimeCycles > 0 then automatically stop it after that many CPU clock cycles. +// If runtimeCycles > 0 then automatically stop it after that many CPU clock cycles, relative to the next +// full period. +// If waveform is not yet started on pin, and on pin == alignPhase a waveform is running, +// the new waveform is started at phaseOffsetCcys phase offset, in CPU clock cycles, to that. +// Setting autoPwm to true allows the wave generator to maintain PWM duty to idle cycle ratio +// under load, for applications where frequency or duty cycle must not change, leave false. // Returns true or false on success or failure. -int startWaveformClockCycles(uint8_t pin, uint32_t timeHighCycles, uint32_t timeLowCycles, uint32_t runTimeCycles); +int startWaveformClockCycles(uint8_t pin, uint32_t timeHighCcys, uint32_t timeLowCcys, + uint32_t runTimeCcys = 0, int8_t alignPhase = -1, uint32_t phaseOffsetCcys = 0, bool autoPwm = false); // Stop a waveform, if any, on the specified pin. // Returns true or false on success or failure. int stopWaveform(uint8_t pin); diff --git a/cores/esp8266/core_esp8266_wiring_pwm.cpp b/cores/esp8266/core_esp8266_wiring_pwm.cpp index b4991310d..6f655716d 100644 --- a/cores/esp8266/core_esp8266_wiring_pwm.cpp +++ b/cores/esp8266/core_esp8266_wiring_pwm.cpp @@ -45,8 +45,8 @@ extern void __analogWriteResolution(int res) { extern void __analogWriteFreq(uint32_t freq) { if (freq < 100) { analogFreq = 100; - } else if (freq > 40000) { - analogFreq = 40000; + } else if (freq > 60000) { + analogFreq = 60000; } else { analogFreq = freq; } @@ -63,22 +63,22 @@ extern void __analogWrite(uint8_t pin, int val) { val = analogScale; } + if (analogMap & 1UL << pin) { // Per the Arduino docs at https://www.arduino.cc/reference/en/language/functions/analog-io/analogwrite/ // val: the duty cycle: between 0 (always off) and 255 (always on). // So if val = 0 we have digitalWrite(LOW), if we have val==range we have digitalWrite(HIGH) - analogMap &= ~(1 << pin); + analogMap &= ~(1 << pin); + } + else { + pinMode(pin, OUTPUT); + } uint32_t high = (analogPeriod * val) / analogScale; uint32_t low = analogPeriod - high; - pinMode(pin, OUTPUT); - if (low == 0) { - digitalWrite(pin, HIGH); - } else if (high == 0) { - digitalWrite(pin, LOW); - } else { - if (startWaveformClockCycles(pin, high, low, 0)) { - analogMap |= (1 << pin); - } + // Find the first GPIO being generated by checking GCC's find-first-set (returns 1 + the bit of the first 1 in an int32_t) + int phaseReference = __builtin_ffs(analogMap) - 1; + if (startWaveformClockCycles(pin, high, low, 0, phaseReference, 0, true)) { + analogMap |= (1 << pin); } } diff --git a/libraries/Servo/src/Servo.cpp b/libraries/Servo/src/Servo.cpp index aff9afebb..cacbbebba 100644 --- a/libraries/Servo/src/Servo.cpp +++ b/libraries/Servo/src/Servo.cpp @@ -69,8 +69,8 @@ uint8_t Servo::attach(int pin, uint16_t minUs, uint16_t maxUs) uint8_t Servo::attach(int pin, uint16_t minUs, uint16_t maxUs, int value) { if (!_attached) { - digitalWrite(pin, LOW); pinMode(pin, OUTPUT); + digitalWrite(pin, LOW); _pin = pin; _attached = true; } @@ -115,7 +115,9 @@ void Servo::writeMicroseconds(int value) _valueUs = value; if (_attached) { _servoMap &= ~(1 << _pin); - if (startWaveform(_pin, _valueUs, REFRESH_INTERVAL - _valueUs, 0)) { + // Find the first GPIO being generated by checking GCC's find-first-set (returns 1 + the bit of the first 1 in an int32_t) + int phaseReference = __builtin_ffs(_servoMap) - 1; + if (startWaveform(_pin, _valueUs, REFRESH_INTERVAL - _valueUs, 0, phaseReference)) { _servoMap |= (1 << _pin); } }