/******************************************************************************
 * @file     system_M451Series.c
 * @version  V0.10
 * $Revision: 11 $
 * $Date: 15/09/02 10:02a $
 * @brief    CMSIS Cortex-M4 Core Peripheral Access Layer Source File for M451 Series MCU
 *
 * @note
 * Copyright (C) 2013~2015 Nuvoton Technology Corp. All rights reserved.
*****************************************************************************/

#include "M451Series.h"


/*----------------------------------------------------------------------------
  DEFINES
 *----------------------------------------------------------------------------*/


/*----------------------------------------------------------------------------
  Clock Variable definitions
 *----------------------------------------------------------------------------*/
uint32_t SystemCoreClock  = __SYSTEM_CLOCK;    /*!< System Clock Frequency (Core Clock)*/
uint32_t CyclesPerUs      = (__HSI / 1000000); /* Cycles per micro second */
uint32_t PllClock         = __HSI;             /*!< PLL Output Clock Frequency         */
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
}

/**
 * Initialize the system
 *
 * @param  None
 * @return None
 *
 * @brief  Setup the microcontroller system.
 *         Initialize the System.
 */
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();


#if 0
    // NOTE: C-runtime not initialized yet. Ensure no static memory (global variable) are accessed in this function.
    nu_ebi_init();
#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

}

#if 0
void nu_ebi_init(void)
{
    // TO BE CONTINUED
}
#endif
/*** (C) COPYRIGHT 2013~2015 Nuvoton Technology Corp. ***/