system_stm32f10x.c文件内容分析

这个文件完成了写声明配置，他和对应的头文件的关系，头文件里做了些什么工作，为什么要这样
完成系统时钟的配置。

#include "STM32f10x.h"
#if defined (STM32F10X_LD_VL) || (defined STM32F10X_MD_VL) || (defined STM32F10X_HD_VL)
#define SYSCLK_FREQ_24MHz 24000000
#else
#define SYSCLK_FREQ_72MHz 72000000
#endif
#if defined (STM32F10X_HD) || (defined STM32F10X_XL) || (defined STM32F10X_HD_VL)
#endif
#define VECT_TAB_OFFSET 0x0
#ifdef SYSCLK_FREQ_HSE
uint32_t SystemCoreClock = SYSCLK_FREQ_HSE;
#elif defined SYSCLK_FREQ_24MHz
uint32_t SystemCoreClock = SYSCLK_FREQ_24MHz;
#elif defined SYSCLK_FREQ_36MHz
uint32_t SystemCoreClock = SYSCLK_FREQ_36MHz;
#elif defined SYSCLK_FREQ_48MHz
uint32_t SystemCoreClock = SYSCLK_FREQ_48MHz;
#elif defined SYSCLK_FREQ_56MHz
uint32_t SystemCoreClock = SYSCLK_FREQ_56MHz;
#elif defined SYSCLK_FREQ_72MHz
uint32_t SystemCoreClock = SYSCLK_FREQ_72MHz;
#else
uint32_t SystemCoreClock = HSI_VALUE;
#endif
__I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
static void SetSysClock(void);
#ifdef SYSCLK_FREQ_HSE
static void SetSysClockToHSE(void);
#elif defined SYSCLK_FREQ_24MHz
static void SetSysClockTo24(void);
#elif defined SYSCLK_FREQ_36MHz
static void SetSysClockTo36(void);
#elif defined SYSCLK_FREQ_48MHz
static void SetSysClockTo48(void);
#elif defined SYSCLK_FREQ_56MHz
static void SetSysClockTo56(void);
#elif defined SYSCLK_FREQ_72MHz
static void SetSysClockTo72(void);
#endif
#ifdef DATA_IN_ExtSRAM
static void SystemInit_ExtMemCtl(void);
#endif
void SystemInit (void)
{
RCC->CR |= (uint32_t)0x00000001;
#ifndef STM32F10X_CL
RCC->CFGR &= (uint32_t)0xF8FF0000;
#else
RCC->CFGR &= (uint32_t)0xF0FF0000;
#endif
RCC->CR &= (uint32_t)0xFEF6FFFF;
RCC->CR &= (uint32_t)0xFFFBFFFF;
RCC->CFGR &= (uint32_t)0xFF80FFFF;
#ifdef STM32F10X_CL
RCC->CR &= (uint32_t)0xEBFFFFFF;
RCC->CIR = 0x00FF0000;
RCC->CFGR2 = 0x00000000;
#elif defined (STM32F10X_LD_VL) || defined (STM32F10X_MD_VL) || (defined STM32F10X_HD_VL)
RCC->CIR = 0x009F0000;
RCC->CFGR2 = 0x00000000;
#else
RCC->CIR = 0x009F0000;
#endif
#if defined (STM32F10X_HD) || (defined STM32F10X_XL) || (defined STM32F10X_HD_VL)
#ifdef DATA_IN_ExtSRAM
SystemInit_ExtMemCtl();
#endif
#endif
SetSysClock();
#ifdef VECT_TAB_SRAM
SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET;
#else
SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET;
#endif
}
void SystemCoreClockUpdate (void)
{
uint32_t tmp = 0, pllmull = 0, pllsource = 0;
#ifdef STM32F10X_CL
uint32_t prediv1source = 0, prediv1factor = 0, prediv2factor = 0, pll2mull = 0;
#endif
#if defined (STM32F10X_LD_VL) || defined (STM32F10X_MD_VL) || (defined STM32F10X_HD_VL)
uint32_t prediv1factor = 0;
#endif
tmp = RCC->CFGR & RCC_CFGR_SWS;
switch (tmp)
{
case 0x00:
SystemCoreClock = HSI_VALUE;
break;
case 0x04:
SystemCoreClock = HSE_VALUE;
break;
case 0x08:
pllmull = RCC->CFGR & RCC_CFGR_PLLMULL;
pllsource = RCC->CFGR & RCC_CFGR_PLLSRC;
#ifndef STM32F10X_CL
pllmull = ( pllmull >> 18) + 2;
if (pllsource == 0x00)
{
SystemCoreClock = (HSI_VALUE >> 1) * pllmull;
}
else
{
#if defined (STM32F10X_LD_VL) || defined (STM32F10X_MD_VL) || (defined STM32F10X_HD_VL)
prediv1factor = (RCC->CFGR2 & RCC_CFGR2_PREDIV1) + 1;
SystemCoreClock = (HSE_VALUE / prediv1factor) * pllmull;
#else
if ((RCC->CFGR & RCC_CFGR_PLLXTPRE) != (uint32_t)RESET)
{
SystemCoreClock = (HSE_VALUE >> 1) * pllmull;
}
else
{
SystemCoreClock = HSE_VALUE * pllmull;
}
#endif
}
#else
pllmull = pllmull >> 18;
if (pllmull != 0x0D)
{
pllmull += 2;
}
else
{
pllmull = 13 / 2;
}
if (pllsource == 0x00)
{
SystemCoreClock = (HSI_VALUE >> 1) * pllmull;
}
else
{
prediv1source = RCC->CFGR2 & RCC_CFGR2_PREDIV1SRC;
prediv1factor = (RCC->CFGR2 & RCC_CFGR2_PREDIV1) + 1;
if (prediv1source == 0)
{
SystemCoreClock = (HSE_VALUE / prediv1factor) * pllmull;
}
else
{
prediv2factor = ((RCC->CFGR2 & RCC_CFGR2_PREDIV2) >> 4) + 1;
pll2mull = ((RCC->CFGR2 & RCC_CFGR2_PLL2MUL) >> 8 ) + 2;
SystemCoreClock = (((HSE_VALUE / prediv2factor) * pll2mull) / prediv1factor) * pllmull;
}
}
#endif
break;
default:
SystemCoreClock = HSI_VALUE;
break;
}
tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)];
SystemCoreClock >>= tmp;
}
static void SetSysClock(void)
{
#ifdef SYSCLK_FREQ_HSE
SetSysClockToHSE();
#elif defined SYSCLK_FREQ_24MHz
SetSysClockTo24();
#elif defined SYSCLK_FREQ_36MHz
SetSysClockTo36();
#elif defined SYSCLK_FREQ_48MHz
SetSysClockTo48();
#elif defined SYSCLK_FREQ_56MHz
SetSysClockTo56();
#elif defined SYSCLK_FREQ_72MHz
SetSysClockTo72();
#endif
}
#ifdef DATA_IN_ExtSRAM
void SystemInit_ExtMemCtl(void)
{
RCC->AHBENR = 0x00000114;
RCC->APB2ENR = 0x000001E0;
GPIOD->CRL = 0x44BB44BB;
GPIOD->CRH = 0xBBBBBBBB;
GPIOE->CRL = 0xB44444BB;
GPIOE->CRH = 0xBBBBBBBB;
GPIOF->CRL = 0x44BBBBBB;
GPIOF->CRH = 0xBBBB4444;
GPIOG->CRL = 0x44BBBBBB;
GPIOG->CRH = 0x44444B44;
FSMC_Bank1->BTCR[4] = 0x00001011;
FSMC_Bank1->BTCR[5] = 0x00000200;
}
#endif
#ifdef SYSCLK_FREQ_HSE
static void SetSysClockToHSE(void)
{
__IO uint32_t StartUpCounter = 0, HSEStatus = 0;
RCC->CR |= ((uint32_t)RCC_CR_HSEON);
do
{
HSEStatus = RCC->CR & RCC_CR_HSERDY;
StartUpCounter++;
} while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSERDY) != RESET)
{
HSEStatus = (uint32_t)0x01;
}
else
{
HSEStatus = (uint32_t)0x00;
}
if (HSEStatus == (uint32_t)0x01)
{
#if !defined STM32F10X_LD_VL && !defined STM32F10X_MD_VL && !defined STM32F10X_HD_VL
FLASH->ACR |= FLASH_ACR_PRFTBE;
FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);
#ifndef STM32F10X_CL
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_0;
#else
if (HSE_VALUE <= 24000000)
{
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_0;
}
else
{
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_1;
}
#endif
#endif
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV1;
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_HSE;
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x04)
{
}
}
else
{
}
}
#elif defined SYSCLK_FREQ_24MHz
static void SetSysClockTo24(void)
{
__IO uint32_t StartUpCounter = 0, HSEStatus = 0;
RCC->CR |= ((uint32_t)RCC_CR_HSEON);
do
{
HSEStatus = RCC->CR & RCC_CR_HSERDY;
StartUpCounter++;
} while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSERDY) != RESET)
{
HSEStatus = (uint32_t)0x01;
}
else
{
HSEStatus = (uint32_t)0x00;
}
if (HSEStatus == (uint32_t)0x01)
{
#if !defined STM32F10X_LD_VL && !defined STM32F10X_MD_VL && !defined STM32F10X_HD_VL
FLASH->ACR |= FLASH_ACR_PRFTBE;
FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_0;
#endif
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV1;
#ifdef STM32F10X_CL
RCC->CFGR &= (uint32_t)~(RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLSRC | RCC_CFGR_PLLMULL);
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLSRC_PREDIV1 |
RCC_CFGR_PLLMULL6);
RCC->CFGR2 &= (uint32_t)~(RCC_CFGR2_PREDIV2 | RCC_CFGR2_PLL2MUL |
RCC_CFGR2_PREDIV1 | RCC_CFGR2_PREDIV1SRC);
RCC->CFGR2 |= (uint32_t)(RCC_CFGR2_PREDIV2_DIV5 | RCC_CFGR2_PLL2MUL8 |
RCC_CFGR2_PREDIV1SRC_PLL2 | RCC_CFGR2_PREDIV1_DIV10);
RCC->CR |= RCC_CR_PLL2ON;
while((RCC->CR & RCC_CR_PLL2RDY) == 0)
{
}
#elif defined (STM32F10X_LD_VL) || defined (STM32F10X_MD_VL) || defined (STM32F10X_HD_VL)
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_PREDIV1 | RCC_CFGR_PLLXTPRE_PREDIV1_Div2 | RCC_CFGR_PLLMULL6);
#else
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLXTPRE_HSE_Div2 | RCC_CFGR_PLLMULL6);
#endif
RCC->CR |= RCC_CR_PLLON;
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x08)
{
}
}
else
{
}
}
#elif defined SYSCLK_FREQ_36MHz
static void SetSysClockTo36(void)
{
__IO uint32_t StartUpCounter = 0, HSEStatus = 0;
RCC->CR |= ((uint32_t)RCC_CR_HSEON);
do
{
HSEStatus = RCC->CR & RCC_CR_HSERDY;
StartUpCounter++;
} while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSERDY) != RESET)
{
HSEStatus = (uint32_t)0x01;
}
else
{
HSEStatus = (uint32_t)0x00;
}
if (HSEStatus == (uint32_t)0x01)
{
FLASH->ACR |= FLASH_ACR_PRFTBE;
FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_1;
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV1;
#ifdef STM32F10X_CL
RCC->CFGR &= (uint32_t)~(RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLSRC | RCC_CFGR_PLLMULL);
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLSRC_PREDIV1 |
RCC_CFGR_PLLMULL9);
RCC->CFGR2 &= (uint32_t)~(RCC_CFGR2_PREDIV2 | RCC_CFGR2_PLL2MUL |
RCC_CFGR2_PREDIV1 | RCC_CFGR2_PREDIV1SRC);
RCC->CFGR2 |= (uint32_t)(RCC_CFGR2_PREDIV2_DIV5 | RCC_CFGR2_PLL2MUL8 |
RCC_CFGR2_PREDIV1SRC_PLL2 | RCC_CFGR2_PREDIV1_DIV10);
RCC->CR |= RCC_CR_PLL2ON;
while((RCC->CR & RCC_CR_PLL2RDY) == 0)
{
}
#else
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLXTPRE_HSE_Div2 | RCC_CFGR_PLLMULL9);
#endif
RCC->CR |= RCC_CR_PLLON;
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x08)
{
}
}
else
{
}
}
#elif defined SYSCLK_FREQ_48MHz
static void SetSysClockTo48(void)
{
__IO uint32_t StartUpCounter = 0, HSEStatus = 0;
RCC->CR |= ((uint32_t)RCC_CR_HSEON);
do
{
HSEStatus = RCC->CR & RCC_CR_HSERDY;
StartUpCounter++;
} while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSERDY) != RESET)
{
HSEStatus = (uint32_t)0x01;
}
else
{
HSEStatus = (uint32_t)0x00;
}
if (HSEStatus == (uint32_t)0x01)
{
FLASH->ACR |= FLASH_ACR_PRFTBE;
FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_1;
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV2;
#ifdef STM32F10X_CL
RCC->CFGR2 &= (uint32_t)~(RCC_CFGR2_PREDIV2 | RCC_CFGR2_PLL2MUL |
RCC_CFGR2_PREDIV1 | RCC_CFGR2_PREDIV1SRC);
RCC->CFGR2 |= (uint32_t)(RCC_CFGR2_PREDIV2_DIV5 | RCC_CFGR2_PLL2MUL8 |
RCC_CFGR2_PREDIV1SRC_PLL2 | RCC_CFGR2_PREDIV1_DIV5);
RCC->CR |= RCC_CR_PLL2ON;
while((RCC->CR & RCC_CR_PLL2RDY) == 0)
{
}
RCC->CFGR &= (uint32_t)~(RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLSRC | RCC_CFGR_PLLMULL);
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLSRC_PREDIV1 |
RCC_CFGR_PLLMULL6);
#else
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLMULL6);
#endif
RCC->CR |= RCC_CR_PLLON;
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x08)
{
}
}
else
{
}
}
#elif defined SYSCLK_FREQ_56MHz
static void SetSysClockTo56(void)
{
__IO uint32_t StartUpCounter = 0, HSEStatus = 0;
RCC->CR |= ((uint32_t)RCC_CR_HSEON);
do
{
HSEStatus = RCC->CR & RCC_CR_HSERDY;
StartUpCounter++;
} while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSERDY) != RESET)
{
HSEStatus = (uint32_t)0x01;
}
else
{
HSEStatus = (uint32_t)0x00;
}
if (HSEStatus == (uint32_t)0x01)
{
FLASH->ACR |= FLASH_ACR_PRFTBE;
FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_2;
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV2;
#ifdef STM32F10X_CL
RCC->CFGR2 &= (uint32_t)~(RCC_CFGR2_PREDIV2 | RCC_CFGR2_PLL2MUL |
RCC_CFGR2_PREDIV1 | RCC_CFGR2_PREDIV1SRC);
RCC->CFGR2 |= (uint32_t)(RCC_CFGR2_PREDIV2_DIV5 | RCC_CFGR2_PLL2MUL8 |
RCC_CFGR2_PREDIV1SRC_PLL2 | RCC_CFGR2_PREDIV1_DIV5);
RCC->CR |= RCC_CR_PLL2ON;
while((RCC->CR & RCC_CR_PLL2RDY) == 0)
{
}
RCC->CFGR &= (uint32_t)~(RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLSRC | RCC_CFGR_PLLMULL);
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLSRC_PREDIV1 |
RCC_CFGR_PLLMULL7);
#else
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLMULL7);
#endif
RCC->CR |= RCC_CR_PLLON;
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x08)
{
}
}
else
{
}
}
#elif defined SYSCLK_FREQ_72MHz
static void SetSysClockTo72(void)
{
__IO uint32_t StartUpCounter = 0, HSEStatus = 0;
RCC->CR |= ((uint32_t)RCC_CR_HSEON);
do
{
HSEStatus = RCC->CR & RCC_CR_HSERDY;
StartUpCounter++;
} while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
if ((RCC->CR & RCC_CR_HSERDY) != RESET)
{
HSEStatus = (uint32_t)0x01;
}
else
{
HSEStatus = (uint32_t)0x00;
}
if (HSEStatus == (uint32_t)0x01)
{
FLASH->ACR |= FLASH_ACR_PRFTBE;
FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);
FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_2;
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV2;
#ifdef STM32F10X_CL
RCC->CFGR2 &= (uint32_t)~(RCC_CFGR2_PREDIV2 | RCC_CFGR2_PLL2MUL |
RCC_CFGR2_PREDIV1 | RCC_CFGR2_PREDIV1SRC);
RCC->CFGR2 |= (uint32_t)(RCC_CFGR2_PREDIV2_DIV5 | RCC_CFGR2_PLL2MUL8 |
RCC_CFGR2_PREDIV1SRC_PLL2 | RCC_CFGR2_PREDIV1_DIV5);
RCC->CR |= RCC_CR_PLL2ON;
while((RCC->CR & RCC_CR_PLL2RDY) == 0)
{
}
RCC->CFGR &= (uint32_t)~(RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLSRC | RCC_CFGR_PLLMULL);
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLSRC_PREDIV1 |
RCC_CFGR_PLLMULL9);
#else
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE |
RCC_CFGR_PLLMULL));
RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLMULL9);
#endif
RCC->CR |= RCC_CR_PLLON;
while((RCC->CR & RCC_CR_PLLRDY) == 0)
{
}
RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x08)
{
}
}
else
{
}
}
#endif

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