How to implement V/f control of 3 phase acim by arduino UNO

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/****************************************************************** 
 * DDS-sinewave - 3phase 
  *   
   ******************************************************************/ 
 
 
#include "avr/pgmspace.h" 
#include "avr/io.h" 
PROGMEM  prog_uchar sine256[] = 
{
  127,130,133,136,139,143,146,149,152,155,158,161,164,167,170,173,176,178,181,184,187,190,192,195,198,200,203,205,208,210,
 212,215,217,219,221,223,225,227,229,231,233,234,236,238,239,240,242,243,244,245,247,248,249,249,250,251,252,252,253,
253,253,254,254,254,254,254,254,254,253,253,253,252,252,251,250,249,249,248,247,245,244,243,242,240,239,238,236,234,
233,231,229,227,225,223,221,219,217,215,212,210,208,205,203,200,198,195,192,190,187,184,181,178,176,173,170,167,164,
161,158,155,152,149,146,143,139,136,133,130,127,124,121,118,115,111,108,105,102,99,96,93,90,87,84,81,78,76,73,70,67,64,
62,59,56,54,51,49,46,44,42,39,37,35,33,31,29,27,25,23,21,20,18,16,15,14,12,11,10,9,7,6,5,5,4,3,2,2,1,1,1,0,0,0,0,0,0,0,1,1,1,2,
2,3,4,5,5,6,7,9,10,11,12,14,15,16,18,20,21,23,25,27,29,31,33,35,37,39,42,44,46,49,51,54,56,59,62,64,67,70,73,76,78,81,84,87,
90,93,96,99,102,105,108,111,115,118,121,124
 
};
 
 
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit)) 
#define PWM_OUT_1 11  // PWM output on pin 11 
#define PWM_OUT_2 10  // PWM output on pin 10 
#define PWM_OUT_3 9  // PWM output on pin 9 
#define LED_PIN  13  // LED status on pin 13 
#define TEST_PIN 7  // Scope trigger on pin 7 
#define POTEN_IN 0  // Potentiometer on pin 0 
#define OFFSET_1 85  // Offset for second-phase
#define OFFSET_2 170  // Offset for third-phase  
 
      double dfreq; 
      const double refclk = 31376.6;  // measured 
      const uint64_t twoTo32 = pow(2, 32); // compute value at startup and use as constant 
      
      
      // variables used inside interrupt service declared as voilatile 
      volatile uint8_t icnt;   // var inside interrupt 
      volatile uint8_t icnt1;   // var inside interrupt 
      volatile uint8_t c4ms;   // counter incremented every 4ms 
      volatile uint32_t phase_accum;  // pahse accumulator 
      volatile uint32_t tword_m;  // dds tuning word m 
      
      
      
   void setup()
   {  
     pinMode(LED_PIN, OUTPUT); 
     // sets the digital pin as output  
     Serial.begin(115200);   // connect to the serial port   
     Serial.println("DDS Test");    
     
      pinMode(TEST_PIN, OUTPUT);         // sets the digital pin as output  
      pinMode(PWM_OUT_1, OUTPUT);       // PWM output / frequency output   
      pinMode(PWM_OUT_2, OUTPUT);       // PWM output / frequency output   
      pinMode(PWM_OUT_3, OUTPUT);       // PWM output / frequency output 
      
     // Setup the timers   
     setup_timer1();   
     setup_timer2(); 
     
       // disable interrupts to avoid timing distortion   
       cbi (TIMSK0, TOIE0);             // disable Timer0 !!! delay() is now not available   
       sbi (TIMSK2, TOIE2);             // enable Timer2 Interrupt  
    dfreq = 1000.0;                // initial output frequency = 1000.0 Hz   
    tword_m = twoTo32 * dfreq / refclk;       // calulate DDS new tuning word  
  } 
  
  
  void loop() 
  {   
    if (c4ms > 250)                // timer / wait for a full second   
    {     
      c4ms = 0;    
      dfreq = analogRead(POTEN_IN);        // read Poti on analog pin 0 to adjust output frequency from 0..1023 Hz  
      cbi (TIMSK2, TOIE2);            // disble Timer2 Interrupt    
      tword_m = twoTo32 * dfreq / refclk;       // calulate DDS new tuning word     
      sbi (TIMSK2, TOIE2);            // enable Timer2 Interrupt   
      Serial.print(dfreq);     
      Serial.print("  ");     
      Serial.println(tword_m);  
    } 
  } 
  
  
   // timer1 setup 
 // set prscaler to 1, PWM mode to phase correct PWM,  16000000/512 = 31.25kHz clock  
    void setup_timer1(void) 
    {   
      // Timer1 Clock Prescaler to : 1   
      sbi (TCCR1B, CS10);   
      cbi (TCCR1B, CS11);   
      cbi (TCCR1B, CS12);  
      // Timer0 PWM Mode set to Phase Correct PWM   
      cbi (TCCR1A, COM1A0);           // clear Compare Match   
      sbi (TCCR1A, COM1A1);   
      cbi (TCCR1A, COM1B0);           // clear Compare Match   
      sbi (TCCR1A, COM1B1);  
      
      sbi (TCCR1A, WGM10);            // Mode 1  / Phase Correct PWM   
      cbi (TCCR1A, WGM11);   
      cbi (TCCR1B, WGM12);   
      cbi (TCCR1B, WGM13); 
    }  
    
    
    // timer2 setup
    // set prscaler to 1, PWM mode to phase correct PWM,  16000000/512 = 31.25kHz clock 
    void setup_timer2(void) 
    {   
      // Timer2 Clock Prescaler to : 1   
      sbi (TCCR2B, CS20);   
      cbi (TCCR2B, CS21);   
      cbi (TCCR2B, CS22);  
  // Timer2 PWM Mode set to Phase Correct PWM   
    cbi (TCCR2A, COM2A0);           // clear Compare Match   
    sbi (TCCR2A, COM2A1);   
    sbi (TCCR2A, WGM20);            // Mode 1  / Phase Correct PWM   
    cbi (TCCR2A, WGM21);   
    cbi (TCCR2B, WGM22); 
    
    }   
    
//****************************************************************** 
// Timer2 Interrupt Service at 31.25kHz = 32us 
// this is the timebase REFCLOCK for the DDS generator 
// FOUT = (M (REFCLK)) / (2 exp 32) 
// runtime : 8 microseconds ( inclusive push and pop) 
ISR(TIMER2_OVF_vect) 
{   
  sbi(PORTD, TEST_PIN);           // Test / set PORTD,TEST_PIN high to observe timing with a oscope  
  phase_accum += tword_m;          // soft DDS, phase accu with 32 bits   
  icnt = phase_accum >> 24;          // use upper 8 bits for phase accu as frequency information  
  OCR2A = pgm_read_byte_near(sine256 + icnt);  // read value fron ROM sine table and send to PWM DAC  
  OCR1A = pgm_read_byte_near(sine256 + (uint8_t)(icnt + OFFSET_1));  
  OCR1B = pgm_read_byte_near(sine256 + (uint8_t)(icnt + OFFSET_2));  
  if (icnt1++ == 125)             // increment variable c4ms every 4 milliseconds   
      {     
        c4ms++;     
      icnt1 = 0;   
      }   
  cbi(PORTD, TEST_PIN);           // reset PORTD,TEST_PIN 
}