Allows user to set (almost) any PWM frequency (#12638)

Marlin/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

Marlin/src/HAL/HAL_AVR/SanityCheck.h

 #endif
 
 /**
+ * Checks for FAST PWM
+ */
+#if ENABLED(FAST_PWM_FAN) && (ENABLED(USE_OCR2A_AS_TOP) && defined(TCCR2))
+    #error "USE_OCR2A_AS_TOP does not apply to devices with a single output TIMER2"
+#endif
+
+/**
  * Sanity checks for Spindle / Laser
  */
 #if ENABLED(SPINDLE_LASER_ENABLE)

Marlin/src/HAL/HAL_AVR/fastio_AVR.h

   WGM_FAST_PWM_OCRnA   // 15  COM OCnA
 };
 
+// Wavefore Generation Modes (Timer 2 only)
+enum WaveGenMode2 : char {
+  WGM2_NORMAL,          // 0
+  WGM2_PWM_PC,          // 1
+  WGM2_CTC_OCR2A,       // 2
+  WGM2_FAST_PWM,        // 3
+  WGM2_reserved_1,      // 4
+  WGM2_PWM_PC_OCR2A,    // 5
+  WGM2_reserved_2,      // 6
+  WGM2_FAST_PWM_OCR2A,  // 7
+};
+
 // Compare Modes
 enum CompareMode : char {
   COM_NORMAL,          //  0
     TCCR##T##B = (TCCR##T##B & ~(0x3 << WGM##T##2)) | (((int(V) >> 2) & 0x3) << WGM##T##2); \
   }while(0)
 #define SET_WGM(T,V) _SET_WGM(T,WGM_##V)
+// Runtime (see Temperature::set_pwm_frequency):
+#define _SET_WGMnQ(TCCRnQ, V) do{ \
+    *(TCCRnQ)[0] = (*(TCCRnQ)[0] & ~(0x3 << 0)) | (( int(V)       & 0x3) << 0); \
+    *(TCCRnQ)[1] = (*(TCCRnQ)[1] & ~(0x3 << 3)) | (((int(V) >> 2) & 0x3) << 3); \
+  }while(0)
 
 // Set Clock Select bits
 // Ex: SET_CS3(PRESCALER_64);
 #define SET_CS4(V) _SET_CS4(CS_##V)
 #define SET_CS5(V) _SET_CS5(CS_##V)
 #define SET_CS(T,V) SET_CS##T(V)
+// Runtime (see Temperature::set_pwm_frequency)
+#define _SET_CSn(TCCRnQ, V) do{ \
+    (*(TCCRnQ)[1] = (*(TCCRnQ[1]) & ~(0x7 << 0)) | ((int(V) & 0x7) << 0)); \
+  }while(0)
 
 // Set Compare Mode bits
 // Ex: SET_COMS(4,CLEAR_SET,CLEAR_SET,CLEAR_SET);
 #define SET_COMB(T,V) SET_COM(T,B,V)
 #define SET_COMC(T,V) SET_COM(T,C,V)
 #define SET_COMS(T,V1,V2,V3) do{ SET_COMA(T,V1); SET_COMB(T,V2); SET_COMC(T,V3); }while(0)
+// Runtime (see Temperature::set_pwm_duty)
+#define _SET_COMnQ(TCCRnQ, Q, V) do{ \
+    (*(TCCRnQ)[0] = (*(TCCRnQ)[0] & ~(0x3 << (6-2*(Q)))) | (int(V) << (6-2*(Q)))); \
+  }while(0)
+
+// Set OCRnQ register
+// Runtime (see Temperature::set_pwm_duty):
+#define _SET_OCRnQ(OCRnQ, Q, V) do{ \
+    (*(OCRnQ)[(Q)] = (0x0000) | (int(V) & 0xFFFF)); \
+  }while(0)
+
+// Set ICRn register (one per timer)
+// Runtime (see Temperature::set_pwm_frequency)
+#define _SET_ICRn(ICRn, V) do{ \
+    (*(ICRn) = (0x0000) | (int(V) & 0xFFFF)); \
+  }while(0)
 
 // Set Noise Canceler bit
 // Ex: SET_ICNC(2,1)

Marlin/src/inc/Conditionals_post.h

 #endif
 
 /**
+ * FAST PWM FAN Settings
+ */
+#if ENABLED(FAST_PWM_FAN) && !defined(FAST_PWM_FAN_FREQUENCY)
+  #define FAST_PWM_FAN_FREQUENCY ((F_CPU) / (2 * 255 * 1)) // Fan frequency default
+#endif
+
+/**
  * Bed Probe dependencies
  */
 #if HAS_BED_PROBE

Marlin/src/module/planner.cpp

       #if HAS_FAN2
         thermalManager.soft_pwm_amount_fan[2] = CALC_FAN_SPEED(2);
       #endif
+
+    #elif ENABLED(FAST_PWM_FAN)
+      #if HAS_FAN0
+        thermalManager.set_pwm_duty(FAN_PIN, CALC_FAN_SPEED(0));
+      #endif
+      #if HAS_FAN1
+        thermalManager.set_pwm_duty(FAN1_PIN, CALC_FAN_SPEED(1));
+      #endif
+      #if HAS_FAN2
+        thermalManager.set_pwm_duty(FAN2_PIN, CALC_FAN_SPEED(2));
+      #endif
+
     #else
       #if HAS_FAN0
         analogWrite(FAN_PIN, CALC_FAN_SPEED(0));

Marlin/src/module/temperature.cpp

   #if HAS_FAN0
     SET_OUTPUT(FAN_PIN);
     #if ENABLED(FAST_PWM_FAN)
-      setPwmFrequency(FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      set_pwm_frequency(FAN_PIN, FAST_PWM_FAN_FREQUENCY);
     #endif
   #endif
 
   #if HAS_FAN1
     SET_OUTPUT(FAN1_PIN);
     #if ENABLED(FAST_PWM_FAN)
-      setPwmFrequency(FAN1_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      set_pwm_frequency(FAN1_PIN, FAST_PWM_FAN_FREQUENCY);
     #endif
   #endif
 
   #if HAS_FAN2
     SET_OUTPUT(FAN2_PIN);
     #if ENABLED(FAST_PWM_FAN)
-      setPwmFrequency(FAN2_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      set_pwm_frequency(FAN2_PIN, FAST_PWM_FAN_FREQUENCY);
     #endif
   #endif
 
   #if ENABLED(USE_CONTROLLER_FAN)
     SET_OUTPUT(CONTROLLER_FAN_PIN);
     #if ENABLED(FAST_PWM_FAN)
-      setPwmFrequency(CONTROLLER_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+      set_pwm_frequency(CONTROLLER_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
     #endif
   #endif
 
     #if E0_AUTO_FAN_PIN == FAN1_PIN
       SET_OUTPUT(E0_AUTO_FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(E0_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+        set_pwm_frequency(E0_AUTO_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
       #endif
     #else
       SET_OUTPUT(E0_AUTO_FAN_PIN);
     #if E1_AUTO_FAN_PIN == FAN1_PIN
       SET_OUTPUT(E1_AUTO_FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(E1_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+        set_pwm_frequency(E1_AUTO_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
       #endif
     #else
       SET_OUTPUT(E1_AUTO_FAN_PIN);
     #if E2_AUTO_FAN_PIN == FAN1_PIN
       SET_OUTPUT(E2_AUTO_FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(E2_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+        set_pwm_frequency(E2_AUTO_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
       #endif
     #else
       SET_OUTPUT(E2_AUTO_FAN_PIN);
     #if E3_AUTO_FAN_PIN == FAN1_PIN
       SET_OUTPUT(E3_AUTO_FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(E3_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+        set_pwm_frequency(E3_AUTO_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
       #endif
     #else
       SET_OUTPUT(E3_AUTO_FAN_PIN);
     #if E4_AUTO_FAN_PIN == FAN1_PIN
       SET_OUTPUT(E4_AUTO_FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(E4_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+        set_pwm_frequency(E4_AUTO_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
       #endif
     #else
       SET_OUTPUT(E4_AUTO_FAN_PIN);
     #if E5_AUTO_FAN_PIN == FAN1_PIN
       SET_OUTPUT(E5_AUTO_FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(E5_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+        set_pwm_frequency(E5_AUTO_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
       #endif
     #else
       SET_OUTPUT(E5_AUTO_FAN_PIN);
     #if CHAMBER_AUTO_FAN_PIN == FAN1_PIN
       SET_OUTPUT(CHAMBER_AUTO_FAN_PIN);
       #if ENABLED(FAST_PWM_FAN)
-        setPwmFrequency(CHAMBER_AUTO_FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
+        set_pwm_frequency(CHAMBER_AUTO_FAN_PIN, FAST_PWM_FAN_FREQUENCY);
       #endif
     #else
       SET_OUTPUT(CHAMBER_AUTO_FAN_PIN);
   #endif
 }
 
-#if ENABLED(FAST_PWM_FAN)
 
-  void Temperature::setPwmFrequency(const pin_t pin, int val) {
+#if ENABLED(FAST_PWM_FAN)
+  Temperature::Timer Temperature::get_pwm_timer(pin_t pin) {
     #if defined(ARDUINO) && !defined(ARDUINO_ARCH_SAM)
-      val &= 0x07;
+      uint8_t q = 0;
       switch (digitalPinToTimer(pin)) {
+        // Protect reserved timers (TIMER0 & TIMER1)
         #ifdef TCCR0A
           #if !AVR_AT90USB1286_FAMILY
             case TIMER0A:
           #endif
-          case TIMER0B:                           //_SET_CS(0, val);
-                                                    break;
+          case TIMER0B:
         #endif
         #ifdef TCCR1A
-          case TIMER1A: case TIMER1B:             //_SET_CS(1, val);
-                                                    break;
+          case TIMER1A: case TIMER1B:
         #endif
+                                            break;
         #if defined(TCCR2) || defined(TCCR2A)
           #ifdef TCCR2
-            case TIMER2:
-          #endif
-          #ifdef TCCR2A
-            case TIMER2A: case TIMER2B:
+            case TIMER2: {
+              Temperature::Timer timer = {
+                /*TCCRnQ*/  { &TCCR2, NULL, NULL},
+                /*OCRnQ*/   { (uint16_t*)&OCR2, NULL, NULL},
+                /*ICRn*/      NULL,
+                /*n, q*/      2, 0
+              };
+            }
+          #elif defined TCCR2A
+            #if ENABLED(USE_OCR2A_AS_TOP)
+              case TIMER2A:   break; // protect TIMER2A
+              case TIMER2B: {
+                Temperature::Timer timer = {
+                  /*TCCRnQ*/  { &TCCR2A,  &TCCR2B,  NULL},
+                  /*OCRnQ*/   { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, NULL},
+                  /*ICRn*/      NULL,
+                  /*n, q*/      2, 1
+                };
+                return timer;
+              }
+            #else
+              case TIMER2B:   q += 1;
+              case TIMER2A: {
+                Temperature::Timer timer = {
+                  /*TCCRnQ*/  { &TCCR2A,  &TCCR2B,  NULL},
+                  /*OCRnQ*/   { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, NULL},
+                  /*ICRn*/      NULL,
+                                2, q
+                };
+                return timer;
+              }
+            #endif
           #endif
-                                                    _SET_CS(2, val); break;
         #endif
         #ifdef TCCR3A
-          case TIMER3A: case TIMER3B: case TIMER3C: _SET_CS(3, val); break;
+          case TIMER3C:   q += 1;
+          case TIMER3B:   q += 1;
+          case TIMER3A: {
+            Temperature::Timer timer = {
+              /*TCCRnQ*/  { &TCCR3A,  &TCCR3B,  &TCCR3C},
+              /*OCRnQ*/   { &OCR3A,   &OCR3B,   &OCR3C},
+              /*ICRn*/      &ICR3,
+              /*n, q*/      3, q
+            };
+            return timer;
+          }
         #endif
         #ifdef TCCR4A
-          case TIMER4A: case TIMER4B: case TIMER4C: _SET_CS(4, val); break;
+          case TIMER4C:   q += 1;
+          case TIMER4B:   q += 1;
+          case TIMER4A: {
+            Temperature::Timer timer = {
+              /*TCCRnQ*/  { &TCCR4A,  &TCCR4B,  &TCCR4C},
+              /*OCRnQ*/   { &OCR4A,   &OCR4B,   &OCR4C},
+              /*ICRn*/      &ICR4,
+              /*n, q*/      4, q
+            };
+            return timer;
+          }
         #endif
         #ifdef TCCR5A
-          case TIMER5A: case TIMER5B: case TIMER5C: _SET_CS(5, val); break;
+          case TIMER5C:   q += 1;
+          case TIMER5B:   q += 1;
+          case TIMER5A: {
+            Temperature::Timer timer = {
+              /*TCCRnQ*/  { &TCCR5A,  &TCCR5B,  &TCCR5C},
+              /*OCRnQ*/   { &OCR5A,   &OCR5B,   &OCR5C },
+              /*ICRn*/      &ICR5,
+              /*n, q*/      5, q
+            };
+            return timer;
+          }
         #endif
       }
-    #endif
+      Temperature::Timer timer = {
+          /*TCCRnQ*/  { NULL, NULL, NULL},
+          /*OCRnQ*/   { NULL, NULL, NULL},
+          /*ICRn*/      NULL,
+                        0, 0
+      };
+      return timer;
+    #endif // ARDUINO && !ARDUINO_ARCH_SAM
+  }
+
+  void Temperature::set_pwm_frequency(const pin_t pin, int f_desired) {
+    #if defined(ARDUINO) && !defined(ARDUINO_ARCH_SAM)
+      Temperature::Timer timer = get_pwm_timer(pin);
+      if (timer.n == 0) return; // Don't proceed if protected timer or not recognised
+      uint16_t size;
+      if (timer.n == 2) size = 255; else size = 65535;
+
+      uint16_t res = 255;   // resolution (TOP value)
+      uint8_t j = 0;        // prescaler index
+      uint8_t wgm = 1;      // waveform generation mode
+
+      // Calculating the prescaler and resolution to use to achieve closest frequency
+      if (f_desired != 0) {
+        int f = F_CPU/(2*1024*size) + 1; // Initialize frequency as lowest (non-zero) achievable
+        uint16_t prescaler[] = {0, 1, 8, /*TIMER2 ONLY*/32, 64, /*TIMER2 ONLY*/128, 256, 1024};
+
+        // loop over prescaler values
+        for (uint8_t i = 1; i < 8; i++) {
+          uint16_t res_temp_fast = 255, res_temp_phase_correct = 255;
+          if (timer.n == 2) {
+            // No resolution calculation for TIMER2 unless enabled USE_OCR2A_AS_TOP
+            #if ENABLED(USE_OCR2A_AS_TOP)
+              res_temp_fast = (F_CPU / (prescaler[i] * f_desired)) - 1;
+              res_temp_phase_correct = F_CPU / (2 * prescaler[i] * f_desired);
+            #endif
+          }
+          else {
+            // Skip TIMER2 specific prescalers when not TIMER2
+            if (i == 3 || i == 5) continue;
+            res_temp_fast = (F_CPU / (prescaler[i] * f_desired)) - 1;
+            res_temp_phase_correct = F_CPU / (2 * prescaler[i] * f_desired);
+          }
+
+          LIMIT(res_temp_fast, 1u, size);
+          LIMIT(res_temp_phase_correct, 1u, size);
+          // Calculate frequncies of test prescaler and resolution values
+          int f_temp_fast = F_CPU / (prescaler[i] * (1 + res_temp_fast));
+          int f_temp_phase_correct = F_CPU / (2 * prescaler[i] * res_temp_phase_correct);
+
+          // If FAST values are closest to desired f
+          if (ABS(f_temp_fast - f_desired) < ABS(f - f_desired)
+              && ABS(f_temp_fast - f_desired) <= ABS(f_temp_phase_correct - f_desired)) {
+            // Remember this combination
+            f = f_temp_fast;
+            res = res_temp_fast;
+            j = i;
+            // Set the Wave Generation Mode to FAST PWM
+            if(timer.n == 2){
+              wgm =
+                #if ENABLED(USE_OCR2A_AS_TOP)
+                  WGM2_FAST_PWM_OCR2A;
+                #else
+                  WGM2_FAST_PWM;
+                #endif
+            }
+            else wgm = WGM_FAST_PWM_ICRn;
+          }
+          // If PHASE CORRECT values are closes to desired f
+          else if (ABS(f_temp_phase_correct - f_desired) < ABS(f - f_desired)) {
+            f = f_temp_phase_correct;
+            res = res_temp_phase_correct;
+            j = i;
+            // Set the Wave Generation Mode to PWM PHASE CORRECT
+            if (timer.n == 2) {
+              wgm =
+                #if ENABLED(USE_OCR2A_AS_TOP)
+                  WGM2_PWM_PC_OCR2A;
+                #else
+                  WGM2_PWM_PC;
+                #endif
+            }
+            else wgm = WGM_PWM_PC_ICRn;
+          }
+        }
+      }
+      _SET_WGMnQ(timer.TCCRnQ, wgm);
+      _SET_CSn(timer.TCCRnQ, j);
+
+      if (timer.n == 2) {
+        #if ENABLED(USE_OCR2A_AS_TOP)
+          _SET_OCRnQ(timer.OCRnQ, 0, res);  // Set OCR2A value (TOP) = res
+        #endif
+      }
+      else {
+        _SET_ICRn(timer.ICRn, res);         // Set ICRn value (TOP) = res
+      }
+    #endif // ARDUINO && !ARDUINO_ARCH_SAM
+  }
+
+  void Temperature::set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
+    #if defined(ARDUINO) && !defined(ARDUINO_ARCH_SAM)
+      // If v is 0 or v_size (max), digitalWrite to LOW or HIGH.
+      // Note that digitalWrite also disables pwm output for us (sets COM bit to 0)
+      if (v == 0)
+        digitalWrite(pin, invert);
+      else if (v == v_size)
+        digitalWrite(pin, !invert);
+      else {
+        Temperature::Timer timer = get_pwm_timer(pin);
+        if (timer.n == 0) return; // Don't proceed if protected timer or not recognised
+        // Set compare output mode to CLEAR -> SET or SET -> CLEAR (if inverted)
+        _SET_COMnQ(timer.TCCRnQ, timer.q
+            #ifdef TCCR2
+              + (timer.q == 2) // COM20 is on bit 4 of TCCR2, thus requires q + 1 in the macro
+            #endif
+          , COM_CLEAR_SET + invert
+        );
+
+        uint16_t top;
+        if (timer.n == 2) { // if TIMER2
+          top =
+            #if ENABLED(USE_OCR2A_AS_TOP)
+              *timer.OCRnQ[0] // top = OCR2A
+            #else
+              255 // top = 0xFF (max)
+            #endif
+          ;
+        }
+        else
+          top = *timer.ICRn; // top = ICRn
+
+        _SET_OCRnQ(timer.OCRnQ, timer.q, v * float(top / v_size)); // Scale 8/16-bit v to top value
+      }
+    #endif // ARDUINO && !ARDUINO_ARCH_SAM
   }
 
 #endif // FAST_PWM_FAN

Marlin/src/module/temperature.h

                      soft_pwm_count_fan[FAN_COUNT];
     #endif
 
+    /**
+     * set_pwm_duty (8-bit AVRs only)
+     *  Sets the PWM duty cycle of the provided pin to the provided value
+     *  Optionally allows inverting the duty cycle [default = false]
+     *  Optionally allows changing the maximum size of the provided value to enable finer PWM duty control [default = 255]
+     */
+    #if ENABLED(FAST_PWM_FAN)
+      static void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size=255, const bool invert=false);
+    #endif
+
     #if ENABLED(BABYSTEPPING)
       static volatile int16_t babystepsTodo[3];
     #endif
 
   private:
 
+    /**
+     * (8-bit AVRs only)
+     *
+     * get_pwm_timer
+     *  Grabs timer information and registers of the provided pin
+     *  returns Timer struct containing this information
+     *  Used by set_pwm_frequency, set_pwm_duty
+     *
+     * set_pwm_frequency
+     *  Sets the frequency of the timer corresponding to the provided pin
+     *  as close as possible to the provided desired frequency. Internally
+     *  calculates the required waveform generation mode, prescaler and
+     *  resolution values required and sets the timer registers accordingly.
+     *  NOTE that the frequency is applied to all pins on the timer (Ex OC3A, OC3B and OC3B)
+     *  NOTE that there are limitations, particularly if using TIMER2. (see Configuration_adv.h -> FAST FAN PWM Settings)
+     */
     #if ENABLED(FAST_PWM_FAN)
-      static void setPwmFrequency(const pin_t pin, int val);
+      typedef struct Timer {
+          volatile uint8_t* TCCRnQ[3];  // max 3 TCCR registers per timer
+          volatile uint16_t* OCRnQ[3];  // max 3 OCR registers per timer
+          volatile uint16_t* ICRn;      // max 1 ICR register per timer
+          uint8_t n;                    // the timer number [0->5]
+          uint8_t q;                    // the timer output [0->2] (A->C)
+      } Timer;
+
+      static Timer get_pwm_timer(const pin_t pin);
+      static void set_pwm_frequency(const pin_t pin, int f_desired);
     #endif
 
     static void set_current_temp_raw();

config/default/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/3DFabXYZ/Migbot/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/AlephObjects/TAZ4/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/AliExpress/UM2pExt/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Anet/A2/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Anet/A2plus/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Anet/A6/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Anet/A8/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/AnyCubic/i3/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/ArmEd/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/BIBO/TouchX/cyclops/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/BIBO/TouchX/default/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/BQ/Hephestos/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/BQ/Hephestos_2/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/BQ/WITBOX/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Cartesio/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/CR-10/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/CR-10S/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/CR-10_5S/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/CR-10mini/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/CR-8/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/Ender-2/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/Ender-3/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Creality/Ender-4/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Einstart-S/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Felix/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/FlashForge/CreatorPro/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/FolgerTech/i3-2020/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Formbot/Raptor/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Formbot/T_Rex_2+/Configuration_adv.h

 #define FAN_MIN_PWM 45
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Formbot/T_Rex_3/Configuration_adv.h

 #define FAN_MIN_PWM 64
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Geeetech/A10M/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Geeetech/A20M/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Geeetech/MeCreator2/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Geeetech/Prusa i3 Pro C/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Geeetech/Prusa i3 Pro W/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Infitary/i3-M508/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/JGAurora/A5/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/MakerParts/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Malyan/M150/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Malyan/M200/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Micromake/C1/enhanced/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Mks/Robin/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Mks/Sbase/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/RapideLite/RL200/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/RigidBot/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/SCARA/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Sanguinololu/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/TheBorg/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/TinyBoy2/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Tronxy/X3A/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Tronxy/X5S-2E/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/UltiMachine/Archim1/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/UltiMachine/Archim2/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/VORONDesign/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Velleman/K8200/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Velleman/K8400/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/WASP/PowerWASP/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/Wanhao/Duplicator 6/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/Anycubic/Kossel/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/FLSUN/auto_calibrate/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/FLSUN/kossel/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/FLSUN/kossel_mini/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/Geeetech/Rostock 301/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/MKS/SBASE/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/Tevo Little Monster/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/generic/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/kossel_mini/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/delta/kossel_xl/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/gCreate/gMax1.5+/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/makibox/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/tvrrug/Round2/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**

config/examples/wt150/Configuration_adv.h

 //#define FAN_MIN_PWM 50
 //#define FAN_MAX_PWM 128
 
+/**
+ * FAST PWM FAN Settings
+ *
+ * Use to change the FAST FAN PWM frequency (if enabled in Configuration.h)
+ * Combinations of PWM Modes, prescale values and TOP resolutions are used internally to produce a
+ * frequency as close as possible to the desired frequency.
+ *
+ * FAST_PWM_FAN_FREQUENCY [undefined by default]
+ *   Set this to your desired frequency.
+ *   If left undefined this defaults to F = F_CPU/(2*255*1)
+ *   ie F = 31.4 Khz on 16 MHz microcontrollers or F = 39.2 KHz on 20 MHz microcontrollers
+ *   These defaults are the same as with the old FAST_PWM_FAN implementation - no migration is required
+ *   NOTE: Setting very low frequencies (< 10 Hz) may result in unexpected timer behaviour.
+ *
+ * USE_OCR2A_AS_TOP [undefined by default]
+ *   Boards that use TIMER2 for PWM have limitations resulting in only a few possible frequencies on TIMER2:
+ *   16MHz MCUs: [62.5KHz, 31.4KHz (default), 7.8KHz, 3.92KHz, 1.95KHz, 977Hz, 488Hz, 244Hz, 60Hz, 122Hz, 30Hz]
+ *   20MHz MCUs: [78.1KHz, 39.2KHz (default), 9.77KHz, 4.9KHz, 2.44KHz, 1.22KHz, 610Hz, 305Hz, 153Hz, 76Hz, 38Hz]
+ *   A greater range can be achieved by enabling USE_OCR2A_AS_TOP. But note that this option blocks the use of
+ *   PWM on pin OC2A. Only use this option if you don't need PWM on 0C2A. (Check your schematic.)
+ *   USE_OCR2A_AS_TOP sacrifices duty cycle control resolution to achieve this broader range of frequencies.
+ */
+#if ENABLED(FAST_PWM_FAN)
+  //#define FAST_PWM_FAN_FREQUENCY 31400
+  //#define USE_OCR2A_AS_TOP
+#endif
+
 // @section extruder
 
 /**