HardwareDriver/nuvoton/m451/Device/Nuvoton/M451Series/Source/system_M451Series.c

110 lines
3.2 KiB
C

/******************************************************************************
* @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();
#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 2013~2015 Nuvoton Technology Corp. ***/