system_M4521.c

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/**************************************************************************/
#include "M4521.h"
 
 
/*----------------------------------------------------------------------------
  DEFINES
 *----------------------------------------------------------------------------*/
 
 
/*----------------------------------------------------------------------------
  Clock Variable definitions
 *----------------------------------------------------------------------------*/
uint32_t SystemCoreClock  = __SYSTEM_CLOCK;    
uint32_t CyclesPerUs      = (__HSI / 1000000); /* Cycles per micro second */
uint32_t PllClock         = __HSI;             
uint32_t gau32ClkSrcTbl[] = {__HXT, __LXT, 0, __LIRC, 0, 0, 0, __HIRC};
 
/*----------------------------------------------------------------------------
  Clock functions
 *----------------------------------------------------------------------------*/
void SystemCoreClockUpdate(void)             /* Get Core Clock Frequency      */
{
#if 1
    uint32_t u32Freq, u32ClkSrc;
    uint32_t u32HclkDiv;
 
    /* Update PLL Clock */
    PllClock = CLK_GetPLLClockFreq();
 
    u32ClkSrc = CLK->CLKSEL0 & CLK_CLKSEL0_HCLKSEL_Msk;
 
    if(u32ClkSrc == CLK_CLKSEL0_HCLKSEL_PLL)
    {
        /* Use PLL clock */
        u32Freq = PllClock;
    }
    else
    {
        /* Use the clock sources directly */
        u32Freq = gau32ClkSrcTbl[u32ClkSrc];
    }
 
    u32HclkDiv = (CLK->CLKDIV0 & CLK_CLKDIV0_HCLKDIV_Msk) + 1;
 
    /* Update System Core Clock */
    SystemCoreClock = u32Freq / u32HclkDiv;
 
 
    //if(SystemCoreClock == 0)
    //    __BKPT(0);
 
    CyclesPerUs = (SystemCoreClock + 500000) / 1000000;
#endif
}
 
void SystemInit(void)
{
    /* ToDo: add code to initialize the system
             do not use global variables because this function is called before
             reaching pre-main. RW section maybe overwritten afterwards.          */
 
    SYS_UnlockReg();
    /* One-time POR18 */
    if((SYS->PDID >> 12) == 0x945)
    {
        M32(GCR_BASE+0x14) |= BIT7;
    }
    /* Force to use INV type with HXT */
    CLK->PWRCTL &= ~CLK_PWRCTL_HXTSELTYP_Msk;
    SYS_LockReg();
 
 
#ifdef EBI_INIT
    extern void SYS_Init();
    extern void EBI_Init();
 
    SYS_UnlockReg();
    SYS_Init();
    EBI_Init();
    SYS_LockReg();
#endif
 
    /* FPU settings ------------------------------------------------------------*/
#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
    SCB->CPACR |= ((3UL << 10 * 2) |               /* set CP10 Full Access */
                   (3UL << 11 * 2));               /* set CP11 Full Access */
#endif
 
}
 
/*** (C) COPYRIGHT 2022 Nuvoton Technology Corp. ***/