diff options
Diffstat (limited to 'firmware/src/start/Cstartup_SAM7.c')
| -rw-r--r-- | firmware/src/start/Cstartup_SAM7.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/firmware/src/start/Cstartup_SAM7.c b/firmware/src/start/Cstartup_SAM7.c new file mode 100644 index 0000000..66dbe20 --- /dev/null +++ b/firmware/src/start/Cstartup_SAM7.c @@ -0,0 +1,89 @@ +//*---------------------------------------------------------------------------- +//* 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) +{ + 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 50 Cycle for 1 usecond ( flied MC_FMR->FMCN + AT91C_BASE_MC->MC_FMR = ((AT91C_MC_FMCN) & (48 << 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 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; + +} |