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//*----------------------------------------------------------------------------
//*         ATMEL Microcontroller Software Support  -  ROUSSET  -
//*----------------------------------------------------------------------------
//* The software is delivered "AS IS" without warranty or condition of any
//* kind, either express, implied or statutory. This includes without
//* limitation any warranty or condition with respect to merchantability or
//* fitness for any particular purpose, or against the infringements of
//* intellectual property rights of others.
//*----------------------------------------------------------------------------
//* File Name           : Cstartup_SAM7.c
//* Object              : Low level initializations written in C for GCC Tools
//* Creation            : 12/Jun/04
//* 1.2   28/Feb/05 JPP : LIB change AT91C_WDTC_WDDIS & PLL
//* 1.3   21/Mar/05 JPP : Change PLL Wait time
//*----------------------------------------------------------------------------

// Include the board file description
#include <board.h>

// The following functions must be write in ARM mode this function called directly
// by exception vector
extern void AT91F_Spurious_handler (void);
extern void AT91F_Default_IRQ_handler (void);
extern void AT91F_Default_FIQ_handler (void);

//*----------------------------------------------------------------------------
//* \fn    AT91F_LowLevelInit
//* \brief This function performs very low level HW initialization
//*        this function can be use a Stack, depending the compilation
//*        optimization mode
//*----------------------------------------------------------------------------
void
AT91F_LowLevelInit (void)
{
  volatile int i;
  
  //* Debounce power supply
  for(i=0;i<1024;i++);
  
  AT91PS_PMC pPMC = AT91C_BASE_PMC;
  //* Set Flash Waite sate
  //  Single Cycle Access at Up to 30 MHz, or 40
  //  if MCK = 47923200 I have 50 Cycle for 1 usecond ( flied MC_FMR->FMCN
  AT91C_BASE_MC->MC_FMR = ((AT91C_MC_FMCN) & (48 << 16)) | AT91C_MC_FWS_1FWS;

  //* Set MCK at 47 923 200
  // 1 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));
  // 2 Checking the Main Oscillator Frequency (Optional)
  // 3 Setting PLL and divider:
  // - div by 24 Fin = 0,7680 =(18,432 / 24)
  // - Mul 125: Fout =   96,0000 =(0,7680 *125)
  // 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)
#if 0
  pPMC->PMC_PLLR = ((AT91C_CKGR_DIV & 0x05) |
		    (AT91C_CKGR_PLLCOUNT & (28 << 8)) |
		    (AT91C_CKGR_MUL & (25 << 16)));
#else
  pPMC->PMC_PLLR = ((AT91C_CKGR_DIV & 24) |
		    (AT91C_CKGR_PLLCOUNT & (28 << 8)) |
		    (AT91C_CKGR_MUL & (125 << 16)));
#endif

  // Wait the startup time
  while (!(pPMC->PMC_SR & AT91C_PMC_LOCK));
  while (!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));
  // 4. Selection of Master Clock and Processor Clock
  // select the PLL clock divided by 2
  pPMC->PMC_MCKR = AT91C_PMC_PRES_CLK_2;
  while (!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));

  pPMC->PMC_MCKR |= AT91C_PMC_CSS_PLL_CLK;
  while (!(pPMC->PMC_SR & AT91C_PMC_MCKRDY));

  // Set up the default interrupts handler vectors
  AT91C_BASE_AIC->AIC_SVR[0] = (int) AT91F_Default_FIQ_handler;
  for (i = 1; i < 31; i++)
    {
      AT91C_BASE_AIC->AIC_SVR[i] = (int) AT91F_Default_IRQ_handler;
    }
  AT91C_BASE_AIC->AIC_SPU = (int) AT91F_Spurious_handler;

}