cstartup_sam7.c

at91sam7x256 mac驱动演示程序

//*----------------------------------------------------------------------------
//*         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 IAR
//*                       tools
//* 1.0   08/Sep/04 JPP	: Creation
//* 1.10  10/Sep/04 JPP : Update AT91C_CKGR_PLLCOUNT filed
//*----------------------------------------------------------------------------

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

extern void AT91F_DBGU_Printk(char *);
// 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) @ "ICODE"
{
  int            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 75 Cycle for 1.5 useconde ( flied MC_FMR->FMCN
  AT91C_BASE_MC->MC_FMR = ((AT91C_MC_FMCN)&(75 <<16)) | AT91C_MC_FWS_1FWS ;

  // Watchdog Disable
  AT91C_BASE_WDTC->WDTC_WDMR= AT91C_WDTC_WDDIS;

  // Set MCK at 47 923 200
  
  // 1 Enabling the Main Oscillator:
  // SCK = 1/32768 = 30.51 uSeconde
  // 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 5 Fin = 3,6864 =(18,432 / 5)
  // - Mul 25+1: Fout =	95,8464 =(3,6864 *26)
  // for 96 MHz the erroe is 0.16%
  //eld out NOT USED = 0 Fi
  pPMC->PMC_PLLR = ((AT91C_CKGR_DIV & 5) |
                   (AT91C_CKGR_PLLCOUNT & (28<<8)) |
                   (AT91C_CKGR_MUL & (25<<16)));

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

//*----------------------------------------------------------------------------
//* \fn    AT91F_DataAbort
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_SpuriousHandler() 
{
	AT91F_DBGU_Printk("-F- Spurious Interrupt detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_DataAbort
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_DataAbort() 
{
	AT91F_DBGU_Printk("-F- Data Abort detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_FetchAbort
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_FetchAbort()
{
	AT91F_DBGU_Printk("-F- Prefetch Abort detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_Undef
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_Undef() 
{
	AT91F_DBGU_Printk("-F- Undef detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_UndefHandler
//* \brief This function reports that no handler have been set for current IT
//*----------------------------------------------------------------------------
void AT91F_UndefHandler() 
{
	AT91F_DBGU_Printk("-F- Undef detected\n\r");
	while (1);
}