/**
??******************************************************************************
??*?@file????system_stm32f4xx.c
??*?@author??MCD?Application?Team
??*?@version?V1.7.0
??*?@date????22-April-2016
??*?@brief???CMSIS?Cortex-M4?Device?Peripheral?Access?layer?System?Source?File.
??*??????????This?file?contains?the?system?clock?configuration?for?STM32F4xx?devices.
??*?????????????
??*?1.??This?file?provides?two?functions?and?one?global?variable?to?be?called?from?
??*?????user?application:
??*??????-?SystemInit（）:?Setups?the?system?clock?（System?clock?source?PLL?Multiplier
??*??????????????????????and?Divider?factors?AHB/APBx?prescalers?and?Flash?settings）
??*??????????????????????depending?on?the?configuration?made?in?the?clock?xls?tool.?
??*??????????????????????This?function?is?called?at?startup?just?after?reset?and?
??*??????????????????????before?branch?to?main?program.?This?call?is?made?inside
??*??????????????????????the?“startup_stm32f4xx.s“?file.
??*
??*??????-?SystemCoreClock?variable:?Contains?the?core?clock?（HCLK）?it?can?be?used
??*??????????????????????????????????by?the?user?application?to?setup?the?SysTick?
??*??????????????????????????????????timer?or?configure?other?parameters.
??*?????????????????????????????????????
??*??????-?SystemCoreClockUpdate（）:?Updates?the?variable?SystemCoreClock?and?must
??*?????????????????????????????????be?called?whenever?the?core?clock?is?changed
??*?????????????????????????????????during?program?execution.
??*
??*?2.?After?each?device?reset?the?HSI?（16?MHz）?is?used?as?system?clock?source.
??*????Then?SystemInit（）?function?is?called?in?“startup_stm32f4xx.s“?file?to
??*????configure?the?system?clock?before?to?branch?to?main?program.
??*
??*?3.?If?the?system?clock?source?selected?by?user?fails?to?startup?the?SystemInit（）
??*????function?will?do?nothing?and?HSI?still?used?as?system?clock?source.?User?can?
??*????add?some?code?to?deal?with?this?issue?inside?the?SetSysClock（）?function.
??*
??*?4.?The?default?value?of?HSE?crystal?is?set?to?25MHz?refer?to?“HSE_VALUE“?define
??*????in?“stm32f4xx.h“?file.?When?HSE?is?used?as?system?clock?source?directly?or
??*????through?PLL?and?you?are?using?different?crystal?you?have?to?adapt?the?HSE
??*????value?to?your?own?configuration.
??*
??*?5.?This?file?configures?the?system?clock?as?follows:
??*=============================================================================
??*=============================================================================
??*????????????????????Supported?STM32F40xxx/41xxx?devices
??*-----------------------------------------------------------------------------
??*????????System?Clock?source????????????????????|?PLL?（HSE）
??*-----------------------------------------------------------------------------
??*????????SYSCLK（Hz）?????????????????????????????|?168000000
??*-----------------------------------------------------------------------------
??*????????HCLK（Hz）????????????????????????

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件?????114401??2016-09-19?11:42??lsm6dsl源碼\CORE\core_cm4.h

?????文件?????114403??2015-09-30?01:38??lsm6dsl源碼\CORE\core_cm4.h~RF123d8c.TMP

?????文件??????18323??2015-09-30?01:38??lsm6dsl源碼\CORE\core_cmFunc.h

?????文件??????27908??2015-09-30?01:38??lsm6dsl源碼\CORE\core_cmInstr.h

?????文件??????22947??2015-09-30?01:38??lsm6dsl源碼\CORE\core_cmSimd.h

?????文件??????29604??2016-04-01?19:25??lsm6dsl源碼\CORE\startup_stm32f40_41xxx.s

?????文件?????919428??2016-04-26?18:05??lsm6dsl源碼\CORE\stm32f4xx.h

?????文件??????60305??2016-09-08?16:20??lsm6dsl源碼\CORE\system_stm32f4xx.c

?????文件???????2232??2016-04-01?19:25??lsm6dsl源碼\CORE\system_stm32f4xx.h

?????文件???????6923??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\misc.h

?????文件??????32958??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_adc.h

?????文件??????27317??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_can.h

?????文件??????12443??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_cec.h

?????文件???????2415??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_crc.h

?????文件??????14480??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_cryp.h

?????文件??????14945??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_dac.h

?????文件???????4295??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_dbgmcu.h

?????文件??????12976??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_dcmi.h

?????文件??????42358??2016-04-26?17:52??lsm6dsl源碼\FWlib\inc\stm32f4xx_dfsdm.h

?????文件??????28881??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_dma.h

?????文件??????19700??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_dma2d.h

?????文件??????41447??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_dsi.h

?????文件???????8114??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_exti.h

?????文件??????24838??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_flash.h

?????文件???????3274??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_flash_ramfunc.h

?????文件??????44923??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_fmc.h

?????文件??????19185??2016-04-26?18:52??lsm6dsl源碼\FWlib\inc\stm32f4xx_fmpi2c.h

?????文件??????27180??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_fsmc.h

?????文件??????27229??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_gpio.h

?????文件??????10083??2016-04-01?19:26??lsm6dsl源碼\FWlib\inc\stm32f4xx_hash.h

............此處省略162個文件信息