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#include "AT91SAM7S256.h"

#define   BIT29       0x20000000

void InitFrec(void);
void InitPeriphery(void);

AT91PS_PMC pPMC   = AT91C_BASE_PMC;

void Delay_s (unsigned long a);

//MAIN POINTER
AT91PS_PIO    p_pPio   = AT91C_BASE_PIOA;
AT91PS_PMC    p_pPMC   = AT91C_BASE_PMC;
AT91PS_USART  p_pUSART = AT91C_BASE_US0;
AT91PS_PDC    p_pPDC   = AT91C_BASE_PDC_US0;
AT91PS_MC     p_pMC    = AT91C_BASE_MC;
AT91PS_AIC    p_pAic   = AT91C_BASE_AIC;

void InitFrec(void)
{
  // Disable watchwog
  AT91C_BASE_WDTC->WDTC_WDMR= AT91C_WDTC_WDDIS;

  //Enabling the Main Oscillator:
  //SCK = 1/32768 = 30.51 uSecond
  //Start up time = 8 * 6 / SCK = 56 * 30.51 = 1,46484375 ms
  pPMC->PMC_MOR = (( AT91C_CKGR_OSCOUNT & (0x06 <<8) | AT91C_CKGR_MOSCEN ));
  //Wait the startup time
  while(!(pPMC->PMC_SR & AT91C_PMC_MOSCS));


  //Setting PLL and divider:
  //- div by 5 Fin = 3,6864 =(18,432 / 5)
  //- Mul 25+1: Fout =   95,8464 =(3,6864 *26)
  //for 96 MHz the erroe is 0.16%
  //Field out NOT USED = 0
  //PLLCOUNT pll startup time estimate at : 0.844 ms
  //PLLCOUNT 28 = 0.000844 /(1/32768)
  pPMC->PMC_PLLR = ((AT91C_CKGR_DIV & 3) | (AT91C_CKGR_PLLCOUNT & (28<<8)) | (AT91C_CKGR_MUL & (24<<16)));

  // Wait the startup time
  while(!(pPMC->PMC_SR & AT91C_PMC_LOCK));
  while(!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));

  //Selection of Master Clock and Processor Clock
  //select the PLL clock divided by 2
  pPMC->PMC_MCKR = AT91C_PMC_CSS_PLL_CLK | AT91C_PMC_PRES_CLK_2 ;
  while(!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));

}


void InitPeriphery(void) {

  //enable the clock of the PIO
  p_pPMC->PMC_PCER = 1 << AT91C_ID_PIOA;

  //LED 1
  //configure the PIO Lines corresponding to LED1
  p_pPio->PIO_PER |= BIT29;    //Enable PA29
  p_pPio->PIO_OER |= BIT29;    //Configure in Output
  p_pPio->PIO_CODR |= BIT29;   //set reg to 0

}

//Simple program that blinking leds

//MAIN POINTERS
AT91PS_PIO    m_pPio   = AT91C_BASE_PIOA;

//it's a simple delay
void Delay (unsigned long a) { while (--a!=0); }

int main()
{
  //Init frequency
  InitFrec();
  //Init leds
  InitPeriphery();

  // loop forever
  while(1)
  {
    m_pPio->PIO_CODR = BIT29;  //set reg to 0 (led1 on)
    Delay(5000000);            //simple delay         
    m_pPio->PIO_SODR = BIT29;  //set reg to 1 (led1 off)
    Delay(5000000);             //simple delay
  }
}