//*----------------------------------------------------------------------------
//* \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)
{
int i;
AT91PS_PMC pPMC = AT91C_BASE_PMC;
//* Set Flash Waite sate
// Single Cycle Access at Up to 30 MHz, or 40
AT91C_BASE_MC->MC_FMR = AT91C_MC_FWS_1FWS ;
//* Watchdog Disable
//AT91C_BASE_WDTC->WDTC_WDMR= AT91C_WDTC_WDDIS;
watchdogEnable(5000);
//* Set MCK at 48 054 850
// 1 Enabling the Main Oscillator:
// SCK = 1/32768 = 30.51 uSecond
// Start up time = 8 * 6 / SCK = 56 * 30.51 = 1,46484375 ms
// mthomas-avoid warning pPMC->PMC_MOR = (( AT91C_CKGR_OSCOUNT & (0x06 <<8) | AT91C_CKGR_MOSCEN ));
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 14 Fin = 1.3165 =(18,432 / 14)
// - Mul 72+1: Fout = 96.1097 =(3,6864 *73)
// for 96 MHz the erroe is 0.11%
// 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 & 14 ) |
(AT91C_CKGR_PLLCOUNT & (28<<8)) |
(AT91C_CKGR_MUL & (72<<16)));
// 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 ;
}
void watchdog_init(void) { watchdogEnable(4000); }
