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Delay and Timeout Routine for dsPIC in Hi-Tech dsPICC

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saeed_pk

saeed_pk

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Hi all;
I require Delay routine for Hi-Tech dsPICC, i can't use the file provided in samples folder because it is for 20 MHz i want to use 10 MHz with 16x PLL
please upload code if any one have
 

Most programs require some type of clock for timing. A common approach is to set up one of the timers to interrupt every 1mS and increment a global variable.
You can then have a timer routine. For example:

delay_1mS(50);

There are plenty of timers in a dsPic.
One thing to know about using unsigned ints as timers. You dont have to worry about overflow when subtracting one from the other, you always get the correct result.
Using Mplab C30 compiler but Im sure Hi-Tech is similer. You would need to adjust PR1 value for the correct timing. I use Mplab Sim stopwatch to check by placing a breakpoint in the interrupt routine.

Code: 
/*--- Global sytem clock ---*/

volatile unsigned int sysclock;

/*--- Initialise Timer 1 (Used as system 1mS clock) ---*/

void start_timer_1(void)
  {
  T1CON = 0;                                                                                    
  T1CONbits.TCKPS = 2;  /* Prescaler 1:64 */ 
  IPC0bits.T1IP = 5;    /* High Priority */              
  IEC0bits.T1IE = 1; 
  IFS0bits.T1IF = 0;  
  PR1 = 576;            /* ~1mS */  
  TMR1 = 0;             
  T1CONbits.TON = 1;              
  }

/*--- Timer 1 Interrupt ~1mS system timer ---*/

void __attribute__((__interrupt__, no_auto_psv)) _T1Interrupt(void)
  {
  sysclock++;
  IFS0bits.T1IF = 0; 
  }

/*--- Millisecond delay ---*/

void delay_1mS(unsigned int milliseconds)
  {
  unsigned int timer;

  timer = sysclock;
 
  while((sysclock - timer) < milliseconds){
    ;
    }
  } 

/*--- End of File ---*/
 

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