Library for Arduino Zero variable FREQ./PWM output

Hardware Arduino Zero
2

This below was the starting sketch modified for going to the library:

/* 
    ZERO LIBRARIES - Modified sketch for function separation
    VER. 1.0 - 18.3.2016--- GENUINO ZERO (c.c.) FREQUENCY SKETCH. Provides variable duty
    cycle squarewave on output pin 7. Frequency adjusted  by REG_TCCO_PER and Duty Cycle
    adjusted by  REG_TCC0_CCB3 (0 - 3000) */
   
//DECLARE VARIABLES
int ledPin = 13;
int HZ = 1998; //XXX
int PW = 1000; //YYY
int (timex) = 1000;

 //SETTING UP
// Output XXX HZ PWM on timer TCC0 (11-bit resolution) on D7 for REG_TCC0_PER = YYY

void setup()
{  
pinMode(ledPin, OUTPUT);

  REG_GCLK_GENDIV = GCLK_GENDIV_DIV(3) |          // Divide the 48MHz clock source by divisor 3: 48MHz/3=16MHz
                    GCLK_GENDIV_ID(4);            // Select Generic Clock (GCLK) 4
  while (GCLK->STATUS.bit.SYNCBUSY);              // Wait for synchronization

  REG_GCLK_GENCTRL = GCLK_GENCTRL_IDC |           // Set the duty cycle to 50/50 HIGH/LOW
                     GCLK_GENCTRL_GENEN |         // Enable GCLK4
                     GCLK_GENCTRL_SRC_DFLL48M |   // Set the 48MHz clock source
                     GCLK_GENCTRL_ID(4);          // Select GCLK4
  while (GCLK->STATUS.bit.SYNCBUSY);              // Wait for synchronization

  // Enable the port multiplexer for the 1 PWM channel: timer TCC0 output
  const uint8_t CHANNELS = 1;
  const uint8_t pwmPins[] = { 7 };
  for (uint8_t i = 0; i < CHANNELS; i++)
    {
     PORT->Group[g_APinDescription[pwmPins[i]].ulPort].PINCFG[g_APinDescription[pwmPins[i]].ulPin].bit.PMUXEN = 1;
    }
  // Connect the TCC0 timer to the port outputs - port pins are paired odd PMUO and even PMUXE
  // F & E specify the timers: TCC0, TCC1 and TCC2
  
  PORT->Group[g_APinDescription[6].ulPort].PMUX[g_APinDescription[6].ulPin >> 1].reg = PORT_PMUX_PMUXO_F;

  // Feed GCLK4 to TCC0 and TCC1
  REG_GCLK_CLKCTRL = GCLK_CLKCTRL_CLKEN |         // Enable GCLK4 to TCC0 and TCC1
                     GCLK_CLKCTRL_GEN_GCLK4 |     // Select GCLK4
                     GCLK_CLKCTRL_ID_TCC0_TCC1;   // Feed GCLK4 to TCC0 and TCC1*/
  while (GCLK->STATUS.bit.SYNCBUSY);              // Wait for synchronization

  // Dual slope PWM operation: timers countinuously count up to PER register value then down 0
  REG_TCC0_WAVE |= TCC_WAVE_POL(0xF) |            // Reverse the output polarity on all TCC0 outputs
                   TCC_WAVE_WAVEGEN_DSBOTTOM;    // Setup dual slope PWM on TCC0
  while (TCC0->SYNCBUSY.bit.WAVE);               // Wait for synchronization
  
  // Divide the 16MHz signal by 8 giving 2MHz (0.5us) TCC0 timer tick and enable the outputs
     REG_TCC0_CTRLA |= TCC_CTRLA_PRESCALER_DIV8 |    // Divide GCLK4 by 8
                    TCC_CTRLA_ENABLE;             // Enable the TCC0 output
  while (TCC0->SYNCBUSY.bit.ENABLE);              // Wait for synchronization
  
  delay(timex);
 }

 //OPERATION
void loop() 
{
 Setting();
 blink(2000);
}

void Setting()
{
 /*Each timer counts up to a maximum or TOP value set by the PER register,
  this determines the frequency of the PWM operation:
  20000 = 50Hz, 10000 = 100Hz, 2500  = 400Hz, 2702 = 370Hz */
    
  REG_TCC0_PER = HZ;      // Frequency setting
  while(TCC0->SYNCBUSY.bit.PER);

 /* The CCBx register value corresponds to the pulsewidth in microseconds (us)*/
  
  REG_TCC0_CCB3 = PW;       // TCC0 CCB3 - Duyt Cycle setting
  while(TCC0->SYNCBUSY.bit.CCB3);
} 

void on()
{
 digitalWrite(ledPin, HIGH);
}
 void off()
 {
 digitalWrite(ledPin, LOW);
 }
 
 void blink(int time)
 {
  on();
  delay(time/2);
  off();
  delay(time/2);                        
 }